Chain of Custody Explained: Why It Matters for Legal DNA Tests

Chain of custody is the documented record of how a specimen moves from the participant to the laboratory.

For legal DNA testing, it generally records:

• Who provided the specimen
• Who collected it
• When collection occurred
• Where collection occurred
• How the participant was identified
• How the specimen was labeled
• How it was secured
• How it was transferred
• When it was received by the laboratory

The purpose is to create a traceable history of the specimen from collection through analysis.

A laboratory can accurately analyze the DNA contained in a cheek swab.

However, the laboratory cannot determine from the DNA alone whether:

• The named participant actually supplied the specimen
• Another person supplied it instead
• Two specimens were switched
• The identifying paperwork was accurate
• The sample was handled according to legal requirements

Chain-of-custody procedures address those questions.

They do not change the participant's DNA. They establish the evidentiary reliability of the specimen's identity and handling.

Legal DNA collection generally begins with participant identification.

Adult participants may be required to present acceptable government-issued photo identification.

The collector compares the participant with the identification and records the required information on the laboratory documents.

For minor participants, the process may include:

• Documentation identifying the child
• Identification of the accompanying adult
• Confirmation of the adult's relationship or authority
• Required signatures or consent documentation

The exact documentation can vary by case and laboratory instructions.

The collector obtains the specimen using laboratory-approved materials and procedures.

Cheek-swab collection is common because it is simple, noninvasive, and provides suitable DNA when performed correctly.

During collection, the collector generally:

• Confirms the participant record
• Opens or prepares the approved collection materials
• Collects the specimen
• Labels each item
• Completes the required forms
• Obtains required signatures
• Secures the specimens for transfer

The participants do not take possession of the completed legal collection materials after collection.

Every specimen must remain associated with the correct participant.

The documentation may include:

• Participant name
• Participant role
• Date of birth
• Collection date
• Collector information
• Case number
• Required signatures
• Specimen identifiers
• Photographs or fingerprints when required by the laboratory or case protocol

Incomplete or inconsistent paperwork may delay testing or require recollection.

After collection, the specimens are packaged according to the laboratory's instructions.

The collector is responsible for maintaining control of the materials until they are transferred through the approved delivery process.

This reduces the opportunity for:

• Substitution
• Tampering
• Mislabeling
• Loss
• Unauthorized access
• Unexplained gaps in specimen handling

The laboratory documents receipt and inspects the submission before accepting it for analysis.

A chain-of-custody problem can occur when required procedures are not followed.

Examples may include:

• The participant collects the specimen privately
• Identification is not verified
• Required signatures are missing
• The specimen label does not match the paperwork
• The package is not properly secured
• An unauthorized person handles the specimen
• The collection cannot be linked to the laboratory case
• Required dates or collector information are missing

Depending on the issue, the laboratory may reject the specimen or require a new collection.

NorthStar performs both legal and informational DNA collections in person.

For informational testing:

• The test is intended for private knowledge
• Formal legal identity-verification procedures are not used
• A legal chain of custody is not established
• The result is not intended for official use

For legal testing:

• Participant identities are documented
• Collection is performed under controlled procedures
• Chain-of-custody records are completed
• Specimens are transferred under the laboratory's legal-testing protocol
• The report is prepared as a legal relationship-testing case

An in-person collection does not automatically make a test legal. The required legal documentation and handling procedures must also be followed.

When a person orders informational testing and later learns that the result is needed for court or another official purpose, the original specimen usually cannot be retroactively placed under chain of custody.

The participants generally must complete a new legal collection.

Choosing the correct test at the beginning can prevent:

• Duplicate testing costs
• Additional appointments
• Court delays
• Missed filing deadlines
• Confusion about the report's intended use

NorthStar Lab Services coordinates and performs in-person legal DNA specimen collections throughout Michigan.

NorthStar follows the collection instructions required by its partner laboratory, completes the applicable case documentation, and transfers the specimens for laboratory analysis.

NorthStar does not provide legal advice and cannot guarantee that a particular court, agency, or other authority will accept a report. Customers should confirm case-specific requirements with the receiving authority or their attorney.