Title: Preservation of Evidence in Criminal Cases | Nolo
Headings: Preservation of Evidence in Criminal Cases
Preservation of Evidence in Criminal Cases
Law enforcement officers and prosecutors have a duty to preserve certain kinds of evidence. Learn what they have to keep, and what happens when they don't keep it.
Free Case Evaluation
"In Nolo you can trust."
— The New York Times
Why You Can Trust Us
Featured In
What Kind of Evidence Must Be Preserved?
Alibi evidence
Other kinds of evidence
Who Has to Preserve Evidence?
Private people exempted
What Happens If Evidence Is Lost or Destroyed?
Proving materiality
Proving bad faith
Remedies

Content: The duty also extends to: Local, county, and state investigative agencies. These include not just detectives and investigators, but also administrative, clerical, and forensic staff. Prosecutors. The attorneys prosecuting the case have an obvious duty to preserve evidence, as do people acting under prosecutorial authority (for example, investigators or experts retained by the prosecutor’s office). The Attorney General. In most states and in most cases, the duty to preserve evidence remains even after a defendant has been convicted. Therefore, the duty applies to a state’s Attorney General’s office (which typically handles appeals and post-conviction matters). Private people exempted
The duty to preserve evidence doesn’t extend to private people or agencies unless they have a formal relationship with a law enforcement agency. Thus, if a private DNA lab is hired by the prosecutor to examine blood samples collected from a crime scene, that lab must protect and preserve the evidence and the results of any testing it conducts on the evidence.