Sometimes. California law requires DNA samples from people in specified categories, including adults arrested or charged with a felony under the statute’s operative rule. A particular warrant can separately authorize a sample, and police may seek testing of biological material left on an item. A voluntary request before arrest is different. The answer depends on the person’s status, the authority officers rely on and how they obtain the sample. (Penal Code §§ 296 and 298.1)
Identify which kind of collection is happening
| Situation | What the authority means |
|---|---|
| Officers ask for a voluntary reference swab during an investigation | A request is not the same as a statutory collection duty or a warrant. If it concerns a sex-crime comparison sample, see our guide to a voluntary DNA request. |
| A person is in a category listed by the DNA database law | Penal Code § 296 requires samples for listed statuses. For adults, the statute includes qualifying felony arrests or charges; it does not make every person merely under investigation, or every person arrested for a misdemeanor, subject to that rule. Other listed categories include felony convictions and specified registration or treatment statuses. |
| A judge signed a warrant or order for a sample | Read the actual document: the person, sample type, place, scope and authorized method matter. A warrant for an oral swab is a distinct authority, not a general license to collect DNA from any suspect. |
| Officers test biological material on an item | The location, how the item was left or obtained, who held it, and what testing was performed matter. A discarded item is not automatically equivalent to a compelled cheek swab. |
For a statutory database sample, Penal Code § 298.1 describes procedures following notice and refusal, including when authorized personnel may use reasonable force. It sets conditions involving authorized personnel, training and facility rules; it does not mean force is automatically justified in every encounter. Do not physically resist. Ask calmly what authority is being used and contact counsel as soon as possible. (Penal Code § 298.1(a)–(c))
The arrest category has a constitutional limit
In People v. Buza, the California Supreme Court upheld a booking cheek swab after a valid probable-cause arrest for felony arson, a serious offense. The court did not decide the constitutionality of every other category covered by the DNA Act. The ruling also does not turn an investigative request made before arrest into compulsory collection. (People v. Buza (2018) 4 Cal.5th 658)
A warrant may authorize an oral swab in the particular case. The warrant and supporting materials should be checked for the person and collection it actually authorizes. (People v. Vargas (2009))
Testing an item raises different facts. In People v. Gallego, the court considered a cigarette butt the suspect voluntarily discarded on a public sidewalk. That decision addressed those facts; it does not settle every claim involving involuntarily shed cells, privately held property or a different kind of genetic analysis. (People v. Gallego (2010))
What to preserve for a lawyer
Keep any request form, booking or arrest paperwork, charge information, warrant or order and its attachments, and an inventory or receipt for seized property. Write down when and where the sample was taken, who collected it, what officers said about the authority and whether the sample came from you or an item. For an item, record where it was and how you know it was left or taken. Do not alter, discard or try to retrieve evidence.
An objection to collection does not by itself mean the sample will be excluded or destroyed. Counsel needs to assess the actual authority, the person’s status, the method, the evidence connection and available remedy. Ending a case does not by itself establish that a DNA database profile has been removed; see our separate California DNA database removal guide.
The Law Offices of David S. Chesley can review the collection circumstances and paperwork in a California criminal case. Call (800) 755-5174.