Witness Interviews in Internal Investigations: The US Perspective

13.1 Introduction

The success of an internal investigation often hinges on the employee (or former employee) interview. While the interview itself may be long or short, it always requires careful consideration and preparation.

Internal investigations are conducted in many different circumstances and for many different reasons. An investigation may be focused on a single instance of alleged misconduct or on the root causes of a corporate failure where no particular individual is believed to be culpable. It may be purely internal, with or without a whistleblower allegation, or it may follow a criminal subpoena or regulatory agency request. Investigations are highly fact-specific, and most interview practices should be tailored accordingly. There are, however, key considerations that typically apply to all witness interviews. This chapter outlines certain best practices in preparing for and conducting witness interviews and memorialising findings.

13.2 Preparing for the interview

13.2.1 Timing

At the outset of an internal investigation, it is tempting to move immediately to interviews, as that may seem the shortest path to learning the key facts. While that sometimes makes sense, jumping into interviews without proper preparation can be counterproductive.

Generally speaking, it is advisable to conduct most interviews after a thorough review and analysis of the documentary evidence. This allows the practitioner to conduct interviews with a more thorough understanding of the facts and to question witnesses about key documents, leading to more developed findings. This can delay the investigation, but it can also obviate the need to conduct two or more rounds of interviews, reducing business disruption and investigation costs. In some instances, conducting interviews before the documentary evidence is available may be required if, for example, a key witness is leaving the organisation.

In certain circumstances, it may also make sense to conduct scoping interviews before document collection and review begins, or while that stage is ongoing. Scoping interviews may assist in tailoring the investigation and identifying key evidence or helpful background, such as relevant policies and practices, the organisation of a particular department or information relevant to data collection. Typically, and where possible, the witnesses interviewed in the investigation scoping phase should not be connected to the events under investigation. Examples include individuals involved in document retention or individuals in control functions who can provide perspective on company policies and practices.

The decision to conduct scoping interviews should be made strategically, balancing considerations such as the risk of tipping off individuals against the benefit of information that can scope the investigation effectively.

13.2.2 Sequencing

Sequencing of interviews is another important consideration. As a rule of thumb, key witnesses should be interviewed later in the investigation so the practitioner can use the information gained beforehand to question them and to reduce the likelihood of a second interview (which is not always possible). Supervisors and senior management should generally be interviewed towards the end of an investigation as well to develop an understanding of management’s knowledge of, or participation in, the conduct at issue. It is critical that interviews of senior managers be conducted with the fullest understanding of the underlying facts. Of course, the sequence may need to be adjusted depending on witness availability.

A related question is whether to conduct certain interviews in parallel or in rapid succession to reduce the risk that witnesses tip each other off to the investigation’s focus, certain lines of questioning or the existence of certain documentary evidence. Each witness’s recollection should be as pristine as possible, not muddied by the recollections of others or the opportunity to reconstruct a narrative, whether intentionally or inadvertently. Should interviews proceed in parallel, practitioners should communicate during or immediately after the interviews so that information learned in one can, where appropriate, be immediately raised in another. Writing up a bulleted list of key takeaways immediately after an interview is often helpful; while full interview memoranda can take longer, bulleted lists are easily created and digested by colleagues and can be an invaluable way of quickly sharing key insights.

Where possible, interviews on the same topic should be conducted around the same time (unless the circumstances merit making an exception). Scheduling the interviews close together may allow the practitioner to more accurately weigh differing perspectives and answers. It also ensures that the investigation is timely completed. Where the investigation is in response to criminal or regulatory inquiries, or may require regulatory reporting, it is essential for the record to be developed and reported promptly. Moreover, a slow-moving investigation is stressful for interviewees and can be bad for the morale of the business unit involved.

13.2.3 Length of interview

Before scheduling it, the practitioner should give careful thought to the appropriate length of the interview. This will depend on several factors, including the interviewee’s anticipated level of knowledge, the complexity of the issues and the amount of documentary evidence to be discussed. Senior managers are also frequently unwilling to sit for lengthy interviews. Generally, it is better to book a longer interview slot than the practitioner thinks is minimally necessary. This provides more time for completeness and follow-up and reduces the risk of requiring further interviews. That said, many interviews can be conducted appropriately in an hour, and they seldom require more than a few hours.

13.2.4 Notifying the interviewee Advance notice and sending calendar invitations

In a typical internal investigation, the interviewee will receive advance notice of an interview.

While this notice may seem like a simple, clerical task, the approach – and who provides the notice – matters. It is frequently preferable for initial notice to be provided by internal counsel or an interviewee’s supervisor, rather than external counsel unknown to the interviewee or senior management. A telephone call may be preferable to an email, with an email following to confirm the specifics.

The notifier should be prepared to respond to any queries and should typically explain that this is confidential, that the witness need not prepare and that more will be explained during the meeting. The sender should also be prepared to explain that the company expects the witness to co-operate. The sender should be prepared to share all correspondence received from the witness with the practitioner in advance of the interview.

If the request for an interview is communicated by email, the timing of the invitation should also be carefully considered. Sending an invitation at a time when the sender is not available to respond promptly – for example, a Friday afternoon – may cause the interviewee unnecessary stress and should be avoided where practicable. Company guidelines may also dictate the requisite advance notice period (e.g., three days).

The information provided to a witness is also important. At a minimum, the invitation should request the interviewee’s presence at a certain place (if in-person) and time and request that the interviewee keep the request confidential. Whether to reveal more context (e.g., advising the interviewee that he or she is the subject of an internal investigation or previewing the topics to be covered) should be dictated by the policies and culture of the particular organisation as well as the needs of the investigation. If the internal investigation is in response to a criminal or regulatory inquiry, there should be additional consideration as to what may be appropriate to share with the witness.

In many cases it is preferable not to provide the interviewee with questions or documents in advance. However, in certain fact-specific cases (e.g., an accounting inquiry where questions may focus on detailed financial data), it might make sense to request that a witness, in preparation for the interview, refresh his or her recollection with respect to a certain issue in advance. An interview may also be more productive if at least some documents are shared in advance so the witness is less likely to demur with respect to recollection of a particular issue, but this must be balanced against the possibility that the witness gives less than candid responses based on a narrative constructed around the documents; one way to mitigate this is to provide some documents in advance but only to show more sensitive ones in the interview. In all cases where material is provided in advance, the practitioner should remember to remind the witness that the investigation is confidential.

Finally, before sending an interview invitation, the practitioner should confirm that the organisation has taken requisite steps (at the outset of the investigation) to preserve evidence that the witness can access. Impromptu interviews

There may be circumstances when advance notice of an interview is at odds with the aims of the investigation, for example, in rapidly developing circumstances, or to avoid the potential for destruction of evidence. This is a strategic decision that should be carefully considered.

13.2.5 Co-operation expectations

Companies may generally require that employees participate in internal investigations, including witness interviews, and this is typically best practice.[2] This expectation is often (and should be) memorialised in a company’s code of conduct, human resources (HR) manual or similar document. Under some circumstances an organisation may threaten termination and subsequently dismiss an employee for refusing to participate in a witness interview. There may be other circumstances in which a company chooses not to require an employee to participate in an interview. For example, the company may not want to put itself in a position of having to follow through on a termination threat with respect to an employee who would be very difficult to promptly replace, or it may not want to risk adverse publicity around a termination or termination threat.

13.2.6 Interviews by non-lawyers or in-house counsel

If a non-lawyer (e.g., HR personnel) leads an interview, there is a risk the interview will not be protected by the attorney–client privilege. To mitigate this, where the interview is intended to be protected by privilege, company counsel should take clear steps to ensure that it is. Specifically, in-house counsel should oversee preparation for the interview, instruct the non-lawyer to conduct the interview and document that instruction, as well as the fact that the purpose of the interview is to obtain facts to provide legal advice to the company.

Likewise, where company counsel conduct an interview, they should be careful to document that their actions are in a legal capacity as opposed to acting as business advisers.

Where the company has an expectation of the attorney–client privilege due to pending litigation or external investigation, for the avoidance of doubt, it is preferable for counsel (either internal or external) to conduct the interview.

13.2.7 Interview attendees: counsel and company representatives

Generally, the fewer people that attend an interview, the more willing a witness is to speak freely. That said, it is best practice for a note-taker, who can later corroborate what happened if needed, to attend along with the interviewer. Where outside counsel is conducting the interview, a company representative may also want to attend. A key strategic question is whether company counsel’s presence will put the witness at ease, resulting in a more productive interview, or whether the witness may be less willing to speak in the presence of a company representative.

Should the company representative plan to join the interview, the practitioner and the company representative should delineate their roles, for example, as to when the company representative will speak, who will pose questions and who will provide the Upjohn warning.

Another issue is how to address an employee’s request to have his or her own counsel attend the interview. The company should consider case by case whether it is legally required to grant this request.[3] In some circumstances, the presence of individual counsel may result in a waiver of privilege where the interests of the employee and the company diverge, as they often do in workplace investigations.[4] In circumstances where the interests converge, it may make sense to explore entering into a common interest agreement and conducting the interview under common interest privilege.

Issues with individual counsel may arise, and it is best to be prepared and set ground rules in advance. For example, typically the employee’s counsel should be asked to make themselves available at the interviewer’s convenience. Individual counsel should also be informed that they are present to observe and provide legal advice as necessary, not to interfere or answer questions on the individual’s behalf. In addition to discussing ground rules, the practitioner may also choose to engage with the employee’s counsel regarding more substantive considerations, for example, to request that the employee refresh his or her recollection with respect to a particular subject matter (e.g., detailed accounting records) prior to the interview.

13.2.8 Group interviews

Group interviews are generally disfavoured as they can muddy individual recollections or encourage interviewees to present a blended, single narrative around key events. However, group scoping interviews may be appropriate where interviewees may more efficiently provide background information and do not have individual exposure. For example, when an interview is focused on how certain operational procedures work at a company, it may be helpful to speak with several people involved in different aspects of those procedures at the same time.

13.2.9 Interviewing former employees

Former employees may possess information relevant or critical to an internal investigation. However, they are typically under no obligation to co-operate in an interview unless explicitly contractually bound (usually in a separation agreement) to do so.

When a former employee agrees to an interview, the practitioner should exercise caution to avoid ethical roadblocks. If a former employee has counsel, that counsel should be informed before the interview takes place, and the former employee should determine with individual counsel whether to co-operate. Frequently, former employees agree to the interview but want their own counsel to be present, and the company will often agree this is the best course. Practitioners should also make it clear that they do not represent the former employee and refrain from providing legal advice, including advice as to whether the former employee should seek legal counsel.[5]

A related issue is the sharing of privileged documents with a former employee, including as part of an investigative interview or in preparation for testimony. Practitioners should exercise caution in this regard, as this could result in waiver of privilege under certain circumstances, including if the communication does not concern information obtained during the course of the former employee’s employment or relate to the former employee’s work[6] or if the former employee requires the information as part of a defence against criminal charges.[7]

13.2.10 In-person and remote interviews

One result of the covid-19 pandemic is that an increasing number of interviews in internal investigations are conducted by videoconference, saving significant time and money.

When deciding whether to proceed with an interview in-person or by videoconference, the practitioner should balance time and cost efficiencies against the potential benefits of an in-person interview: the opportunity to more accurately judge body language and credibility; the chance to build a rapport with the witness; less chance of the witness becoming distracted; the ease of presenting documents; and a greater guarantee of privacy. Frequently, after the interview is concluded and as the participants are preparing to depart, the witness will volunteer useful additional information.

If the interview is conducted by videoconference, the calendar invitation should convey an expectation that the interviewee will join from a private, confidential place with a stable internet connection, and that the interviewee’s camera will be switched on. At the outset, the practitioner should confirm that this is the case and, if necessary, request the interviewee to turn on the video camera.

Should the interview proceed in person, the practitioner should ensure that the location is private and, to the extent possible, out of others’ view and earshot.

13.2.11 Presenting documentary evidence during remote interviews

During a remote interview, the same considerations with respect to sharing documents in advance referenced above will generally apply; it is typically advisable to share documentary evidence through the videoconferencing platform, rather than to send the interviewee soft- or hard-copy binders of evidence in advance. However, it is sometimes challenging to navigate documents on a screen, particularly where the documents are lengthy or technical in nature. In those circumstances, providing copies and asking the witness to review them in advance can avoid significant unproductive interview time. Should the practitioner need to share the evidence in advance, security precautions should be undertaken, such as sending password protected files to the interviewee’s company email address.

When presenting documentary evidence through a videoconferencing platform, the practitioner should exercise caution when sharing a screen to avoid inadvertently projecting the interview outline or other privileged materials. The practitioner should also remember to magnify the document, so it is easy for the interviewee to see.

Depending on personal style, the practitioner may choose to display the documents or ask the note-taker to do so. Should the practitioner rely on the note-taker, the note-taker should already be familiar with the documents to avoid disrupting the interview.

13.2.12 Interview outlines

Practitioners typically prepare summaries of the lines of questioning they plan to cover, and the documents they plan to show the witness. The level of detail required in interview outlines is case-specific and will also depend on the practitioner’s knowledge of the case and personal style. The interview outline should be treated as privileged work-product and not be shared with the interviewee at any stage. An interview outline is rarely followed word for word, and the practitioner should be prepared to deviate in light of the information learned during the interview. It is frequently helpful to consult the outline towards the end of an interview to ensure all relevant topics have been covered. Some practitioners, even if they like to have a lengthy outline, choose to have as the first page a list of bulleted topics to easily check that they have all been covered.

13.2.13 Language considerations and translators

Generally speaking, it is best practice to interview witnesses in their native language. Doing so results in a better and more fulsome interview and will also guard against later allegations that they did not understand what they were being asked. Where a company expects its employees to operate in a certain language, it is typically reasonable to proceed with the interview in that language.

If the practitioner does not speak a language in which the interviewee is professionally fluent, the practitioner should consider whether to employ a translator or, if it is an option, seek the assistance of another practitioner fluent in the language. The benefits of the practitioner well-versed in the case conducting the interview should be balanced against the inefficiencies created by employing a translator, namely that the interview may run twice as long, and that the translation may stop the interview flow and prevent the practitioner from building a rapport with the interviewee.

13.2.14 Witnesses the government may interview

There are special considerations when determining whether to interview a witness whom the government has also expressed interest in interviewing. For one, the practitioner should decide whether to inform the government in advance of the interview, as a courtesy, to alleviate a future government complaint that the company steered the witness. Doing so may result in co-operation credit (official or unofficial) for the company. This must be balanced against the interests of the company in learning what the witness might know and defending the company. This is a nuanced and fact-specific decision that should not be taken lightly.

13.3 Conducting the interview

13.3.1 Upjohn warning

At the outset of an interview, the practitioner should give the interviewee an Upjohn warning making clear that: the practitioner represents the company, not the interviewee; the purpose of the interview is to provide legal advice to the company; the conversation is privileged but the privilege belongs to the company and the company can choose to waive it and share the contents of the interview with a third party; and the interviewee should not discuss the interview with others.[8] Depending on circumstances, and to avoid later claims of mistreatment, it may be advisable to inform the interviewee that the contents of the interview may be specifically shared with the government.

After providing the Upjohn warning, the practitioner should confirm that the interviewee understood it and agrees to proceed. Should the interviewee ask whether he or she needs counsel, the practitioner should state that he or she cannot advise in that regard and that the decision rests with the interviewee; it also may be appropriate to advise the employee that the company expects the employee to co-operate, and that if counsel is obtained, counsel must be available promptly and adhere to the company’s schedule.

Consequences for failing to provide an Upjohn warning are severe for the practitioner and the company. Conflict issues may result from the witness’s belief that the lawyer represents the witness (either in addition to or instead of the company). In an extreme case, a lawyer may be sanctioned[9] or disqualified from representing the company.[10] For its part, the company could lose a claim that the interview was subject to the attorney–client privilege, the ramifications of which could be significant.

The Upjohn warning should generally be provided to both current and former employees.[11]

13.3.2 Interview approach

The practitioner’s approach and tone during the interview will vary depending on a variety of factors, including the individual’s role in the investigation, the severity of the issue, the alleged conduct of the interviewee, the documentary evidence, and the culture of the company in question. Likewise, the practitioner should be prepared to pivot in his or her approach, depending on what is revealed during the interview and the rapport with the interviewee.

13.3.3 Presenting evidence

As a general good practice, the practitioner should only show the interviewee evidence that the interviewee has seen or has been able to access in the normal course of the interviewee’s job. For example, it is frequently preferable to avoid showing the witness an email on which the witness did not appear. In certain circumstances, practitioners may, however, decide to show witnesses documents they have not seen, for example, when it is useful to have them comment on the communications of another individual or to show evasive witnesses that they in fact participated in a meeting or other event.

13.3.4 Concluding the interview

At the conclusion of the interview, the practitioner should ask the note-taker whether anything needs clarification. Likewise, the practitioner may ask the interviewee whether he or she would like to add or clarify based on the topics discussed. It is frequently helpful to ask for copies of any documents that the witness has mentioned at this point. It may also be helpful to ask the witness which other witnesses may have information in connection with the investigation. Finally, the practitioner should conclude the interview by reminding the interviewee to keep the conversation confidential. The practitioner should also provide contact information for a designated contact person if the interviewee recalls any additional information or wants to provide any documentary evidence to aid the investigation.

13.4 Memorialising the findings

13.4.1 Preparing interview memoranda

Verbatim transcripts or recordings of interviews may be challenged as not subject to the attorney–client privilege or the attorney work-product doctrine. To protect from waiver of either, it is best practice to produce interview memoranda, including counsel’s mental impressions and advice, and to do so soon after the interview when the interviewer’s and note-taker’s recollections are fresh.

There are different approaches to preparing interview memoranda. Some practitioners prefer to prepare the memoranda in chronological order, taking down questions and answers. While having the advantage of providing a clear summary, if this record is verbatim (or close to verbatim), it may make it harder to withstand privilege challenges. Other practitioners prefer to organise interview memoranda topically, interweaving the issues raised with the witness and his or her answers, along with attorney thoughts and impressions. This makes a memorandum easier to protect and has the benefit of providing more contemporaneous impressions (for example, with respect to witness credibility) that may fade and not be clear from the factual portions of the memorandum.

The interview memoranda should be prepared by the note-taker, in co-operation with the interviewer, to ensure their accuracy, and they should include salient details, such as the time, date and length of the interview; the interview location; the attendees; and their titles. It should also be clear which documents were shown to the witness. For the reasons discussed above, a memorandum should clearly document that the interviewer provided an Upjohn warning, the contents of that warning and the fact that the interviewee agreed to proceed with the interview. It should also clearly assert that the memorandum is protected from disclosure by the attorney–client privilege and work-product doctrines.

13.4.2 Witness’s requests to review of notes

Witnesses frequently request to review interview notes or memoranda. A practitioner typically should not provide these to a witness, as doing so could constitute a waiver of privilege or work-product; it may also result in unproductive disputes about what the witness said or intended. The act of approving the final interview memorandum could turn it into a witness statement, which may make it harder to avoid a privilege challenge.

13.4.3 Sharing findings with criminal or regulatory authorities

When considering whether to discuss the content of witness interviews with the government, practitioners should exercise particular care. The majority of courts have held that a party waives privilege by disclosing privileged communications to the government.[12] By providing an ‘oral download’ of a witness interview, a practitioner risks waiving privilege over it,[13] which, in turn, may lead to knock-on effects, including having to produce interview memoranda in related private litigation. If there is a strategic need to provide information to the government (for example, as part of a co-operation strategy), a practitioner should be systematic and cautious. Frequently, a client’s interests are best served by providing information from an interview to a government agency, but only after a careful weighing of interests. One potential way of avoiding waiver while satisfying government co-operation requirements is to provide summaries of what was learned in interviews without referencing particular interviewees, for example, by referencing employee functions (e.g., ‘we learned in our interviews with risk personnel that . . .’) or by collating information by topic (e.g., ‘we learned in our interviews that risk personnel often . . .’).

13.5 Conclusion

Witness interviews often provide a key turning point in an internal investigation. The impressions and recollections of a witness will often go beyond the cold record of documents and emails. Careful preparation and planning will help the practitioner avoid common mistakes in interviews and maximise the strategic and fact-finding benefits of the interview.


[1] John Nathanson and Katherine Stoller are partners, and Cáitrín McKiernan is a senior associate, at Shearman & Sterling LLP.

[2] See, e.g., McGrory v. Applied Signal Technology Inc., 212 Cal. App. 4th 1510, 1528 (2013) (holding employment-at-will employees may be terminated for refusing to co-operate with internal investigation). See also Gilman v. Marsh & McLennan Cos., 826 F.3d 69 (2d Cir. 2016).

[3] Employees have no automatic right to counsel during an internal investigation, unless it is contractually provided for under the terms of their employment. Union employees, however, may insist that a union representative attend any investigatory interview that could lead to the employee’s discipline. See N.L.R.B. v. J. Weingarten, Inc., 420 U.S. 251, 256–57, 260 (1975).

[4] See, e.g., Smith v. Tech. House, Ltd., 11th Dist. Portage No. 2018-P-0080, 2019-Ohio-2670, 2019 WL 2746868, ¶ 27; see generally SEC v. Rashid, No. 17-CV-8223 (PKC), 2018 WL 6573451, at *1–2 (S.D.N.Y. 13 December 2018) (discussing common interest privilege).

[5] See, e.g., American Bar Association Model Rule of Prof’l Conduct 4.3 (2022).

[6] See, e.g., Peralta v. Cendant Corp., 190 F.R.D. 38, 41–42 (D. Conn. 1999).

[7] See, e.g., United States v. Grace, 439 F.Supp.2d 1125, 1138–45 (D. Mont. 2006).

[8] See Upjohn Co. v. United States, 449 U.S. 383 (1981).

[9] See, e.g., United States v. Nicholas, 606 F.Supp.2d 1109, 1121 (N.D.Ca. 2009) rev’d sub nom. United States v. Ruehle, 583 F.3d 600 (9th Cir. 2009) (declining to reverse the referral to the state bar for potential disciplinary action).

[10] See, e.g., In re Grand Jury Subpoena: Under Seal, 415 F.3d 333, (4th Cir. 2005) (failure to administer Upjohn warnings would have required attorneys to ‘withdraw from all representation’).

[11] See, e.g., Hanover Ins. Co., v. Plaquemines Parish Gov’t, 304 F.R.D. 494, 498–99 (E.D. La. 2015) (‘[I]t appears that every federal court to address the issue, with the exception of a single district court decision in 1985, has held that the privilege extends to former employees in certain contexts.’); Vegnani v. Medlogix, LLC, No. CV 19-11291-LTS, 2020 WL 5634349, at *2 (D. Mass. Sept. 21, 2020) (‘Those courts which have addressed whether the privilege extends to former employees have largely concluded that it does. . .’); O’Gorman v. Kitchen, No. 20-CV-1404 (LJL), 2021 WL 1292907, at *2 (S.D.N.Y. 7 April 2021) (Upjohn and subsequent decisions ‘recognize that the attorney-client privilege extends to interviews conducted by counsel of current and former employees to gather facts for the purposes of providing legal advice.’)

[12] See, e.g., In re Qwest Comm. Int’l Inc., 450 F.3d 1179, 1185 (10th Cir. 2006) (‘Any voluntary disclosure by the client is inconsistent with the attorney-client relationship and waives the privilege’)(quoting United States v. Bernard, 877 F.2d 1463, 1465 (10th Cir. 1989)); United States v. Deloitte LLP, 610 F.3d 129, 140 (D.C. Cir. 2010); Berkley Custom Ins. Managers v. York Risk Servs. Grp., Inc., No. 18-CV-9297 (LJL), 2020 WL 5439636, at *4 (S.D.N.Y. Sept. 10, 2020).

[13] See, e.g., United States v. Coburn and Schwartz, No. 2:19-cr-00120 (D. N.J., Apr. 27, 2022) (Where outside counsel provided oral ‘downloads’ of privileged witness interviews from internal investigation to the government, and the company was ordered to produce all formerly privileged interview memoranda); SEC v. Herrera, 324 F.R.D. 258, 267 (S.D. Fla. 2017).

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