What is a 'custodian interview' and why should I do one?

  • Subtitle: Tech Support
Written by  Posted Date: July 2, 2012
I find it surprising when litigators choose not to do full “custodian interviews” before beginning the discovery process. An effective custodian interview done at the earliest possible opportunity can improve the discovery process, particularly when electronically stored information is involved.
A custodian interview involves asking people who may have documents relevant to litigation (i.e., custodians) about those documents, where to find them, and what they might contain. Custodian interviews are just old-fashioned lawyering, applied to e-discovery. Custodian interviews are also lawyer work product and, arguably, are subject to litigation privilege.
These types of interviews are useful because they help you to identify all the locations where custodians have paper or electronically stored information and can provide information about which electronic records each person created, received, and accessed, and where these are stored. Information from these interviews can help you preserve and collect potentially relevant documents and identify, at an early stage, those documents that do not need to be collected. Determining early what is available and relevant can ultimately help lower the costs of e-discovery by simplifying the collection process and ensuring that litigation holds are implemented so spoliation and destruction of records is avoided. These interviews can also establish the basis for arguing
proportionality in meet-and-confer conferences or on a discovery motion, because they will provide you with information to show how the cost of collecting or producing electronically stored information may exceed the value of the claim or the utility of the information sought in the litigation.
The best time to do custodian interviews may depend on how the litigation and fact finding is unfolding. I prefer to do them as early as possible and preferably in conjunction with establishing litigation holds to make sure that no potentially relevant information is destroyed. I view custodian interviews as a natural extension of the early fact interviews conducted of individuals with knowledge of the case. Custodian interviews can be understood as another step in gathering information that can be used to advise the client about the possible manner in which the litigation and discovery process may unfold.
There are two categories of custodians to be interviewed: IT custodians and end-user custodians. Where companies or organizations are involved, IT custodians are the people responsible for the overall management of the information technology systems. Where there are extensive paper collections of documents that are systematically organized, a records manager or person responsible for those paper records might also be included in this group. The second category, end-user custodians, includes people who created, received, or accessed the potentially relevant documents at issue. They are asked about their habits and practices in working with documents; about the computing devices and software they used while creating, accessing, or receiving those documents; and about all the locations where those documents might be.
I prefer to do IT custodian interviews first, because with a single interview I can gain valuable insight into company practices and obtain information that may be relevant to multiple end users. I use the IT custodian interview to ask for any applicable IT policies and procedures, including the acceptable use policy and social media policies (if these are relevant); about how the computers are configured; which computer applications people have available; how e-mail is made available to end-users; and to obtain a data map — a diagrammatic representation of the computer system, which will help guide me through the IT systems much like a geographical or topographical map guides me through landscape.
In this age of smartphones and cloud computing, I also ask the IT custodian about peripheral devices that are made available to end-users, and whether the company may store its data outside its own systems. I can also ask the IT department to generate reports about each user’s particular configuration, including available hardware and memory size, the number of e-mail accounts available to a user, and reports on places where that person can store data.
End-user custodian interviews help you understand how each particular user created, received, or accessed documents. You can ask the end-user about what information he or she might have in relation to the issues in the litigation. I also ask about working styles, how they organize or “folder” information, and whether there is any special terminology or naming convention they use that can help me sort through or search information. This information can help me target the preservation and collection of documents and can form the basis for developing search terms for use in searching or reviewing documents. I also find out if the user accessed information through home-computing systems or mobile devices including smartphones. In addition, I ask custodians who else they worked with in order to determine whether the custodian list is complete. Doing so may help me identify other people who should be interviewed.
Some lawyers may feel uncomfortable doing a custodian interview, particularly if they are working with electronically stored information for the first time. It is acceptable to involve an expert, such as a vendor, or a lawyer or clerk specialist, but I recommend that a lawyer with responsibility for case preparation sit in on the interview to make sure the correct information has been collected. A lawyer’s participation in the interview helps ensure the conversations are kept privileged and the focus of the information gathering remains on the issues in dispute.
Finally, as with any witness interview, it is important to take good notes. I can often identify gaps in evidence collection simply by reviewing my notes for the custodians in the aggregate. I also compare my notes from custodian interviews to the evidence collected when this becomes available. Many lawyers will find it unsurprising that evidence witnesses, much like fact witnesses, get the details wrong about their own documents and data or simply aren’t truthful. I find it helpful to learn about these evidentiary misunderstandings and omissions early, and prior to oral discovery.
Photo: Shutterstock
Photo: Shutterstock
I find it surprising when litigators choose not to do full “custodian interviews” before beginning the discovery process. An effective custodian interview done at the earliest possible opportunity can improve the discovery process, particularly when electronically stored information is involved.


A custodian interview involves asking people who may have documents relevant to litigation (i.e., custodians) about those documents, where to find them, and what they might contain. Custodian interviews are just old-fashioned lawyering, applied to e-discovery. Custodian interviews are also lawyer work product and, arguably, are subject to litigation privilege.

These types of interviews are useful because they help you to identify all the locations where custodians have paper or electronically stored information and can provide information about which electronic records each person created, received, and accessed, and where these are stored. Information from these interviews can help you preserve and collect potentially relevant documents and identify, at an early stage, those documents that do not need to be collected. Determining early what is available and relevant can ultimately help lower the costs of e-discovery by simplifying the collection process and ensuring that litigation holds are implemented so spoliation and destruction of records is avoided. These interviews can also establish the basis for arguing proportionality in meet-and-confer conferences or on a discovery motion, because they will provide you with information to show how the cost of collecting or producing electronically stored information may exceed the value of the claim or the utility of the information sought in the litigation.

The best time to do custodian interviews may depend on how the litigation and fact finding is unfolding. I prefer to do them as early as possible and preferably in conjunction with establishing litigation holds to make sure that no potentially relevant information is destroyed. I view custodian interviews as a natural extension of the early fact interviews conducted of individuals with knowledge of the case. Custodian interviews can be understood as another step in gathering information that can be used to advise the client about the possible manner in which the litigation and discovery process may unfold.

There are two categories of custodians to be interviewed: IT custodians and end-user custodians. Where companies or organizations are involved, IT custodians are the people responsible for the overall management of the information technology systems. Where there are extensive paper collections of documents that are systematically organized, a records manager or person responsible for those paper records might also be included in this group. The second category, end-user custodians, includes people who created, received, or accessed the potentially relevant documents at issue. They are asked about their habits and practices in working with documents; about the computing devices and software they used while creating, accessing, or receiving those documents; and about all the locations where those documents might be.

I prefer to do IT custodian interviews first, because with a single interview I can gain valuable insight into company practices and obtain information that may be relevant to multiple end users. I use the IT custodian interview to ask for any applicable IT policies and procedures, including the acceptable use policy and social media policies (if these are relevant); about how the computers are configured; which computer applications people have available; how e-mail is made available to end-users; and to obtain a data map — a diagrammatic representation of the computer system, which will help guide me through the IT systems much like a geographical or topographical map guides me through landscape.

In this age of smartphones and cloud computing, I also ask the IT custodian about peripheral devices that are made available to end-users, and whether the company may store its data outside its own systems. I can also ask the IT department to generate reports about each user’s particular configuration, including available hardware and memory size, the number of e-mail accounts available to a user, and reports on places where that person can store data.

End-user custodian interviews help you understand how each particular user created, received, or accessed documents. You can ask the end-user about what information he or she might have in relation to the issues in the litigation. I also ask about working styles, how they organize or “folder” information, and whether there is any special terminology or naming convention they use that can help me sort through or search information. This information can help me target the preservation and collection of documents and can form the basis for developing search terms for use in searching or reviewing documents. I also find out if the user accessed information through home-computing systems or mobile devices including smartphones. In addition, I ask custodians who else they worked with in order to determine whether the custodian list is complete. Doing so may help me identify other people who should be interviewed.

Some lawyers may feel uncomfortable doing a custodian interview, particularly if they are working with electronically stored information for the first time. It is acceptable to involve an expert, such as a vendor, or a lawyer or clerk specialist, but I recommend that a lawyer with responsibility for case preparation sit in on the interview to make sure the correct information has been collected. A lawyer’s participation in the interview helps ensure the conversations are kept privileged and the focus of the information gathering remains on the issues in dispute.

Finally, as with any witness interview, it is important to take good notes. I can often identify gaps in evidence collection simply by reviewing my notes for the custodians in the aggregate. I also compare my notes from custodian interviews to the evidence collected when this becomes available. Many lawyers will find it unsurprising that evidence witnesses, much like fact witnesses, get the details wrong about their own documents and data or simply aren’t truthful. I find it helpful to learn about these evidentiary misunderstandings and omissions early, and prior to oral discovery.  

Dera J. Nevin is the senior director, litigation support, and e-discovery counsel at McCarthy Tétrault LLP. A practising lawyer, she also oversees the firm’s e-discovery operations and can be reached at This email address is being protected from spambots. You need JavaScript enabled to view it. .

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Dera J. Nevin

Dera J. Nevin is an e-discovery lawyer with a focus on strategic process and technology initiatives, and matter and program cost containment.




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