28 CFR § 28.23 - Evidence subject to the preservation requirement.

---
identifier: "/us/cfr/t28/s28.23"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "28 CFR § 28.23 - Evidence subject to the preservation requirement."
title_number: 28
title_name: "Judicial Administration"
section_number: "28.23"
section_name: "Evidence subject to the preservation requirement."
chapter_name: "DEPARTMENT OF JUSTICE"
part_number: "28"
part_name: "DNA IDENTIFICATION SYSTEM"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "28 U.S.C. 509, 510; 34 U.S.C. 12592, 40702, 40703; 10 U.S.C. 1565; 18 U.S.C. 3600A; Public Law 106-546, 114 Stat. 2726; Public Law 107-56, 115 Stat. 272; Public Law 108-405, 118 Stat. 2260; Public Law 109-162, 119 Stat. 2960; Public Law 109-248, 120 Stat. 587; Public Law 115-50, 131 Stat. 1001."
regulatory_source: "Order No. 2699-2003, 68 FR 74858, Dec. 29, 2003, unless otherwise noted."
cfr_part: "28"
---


# 28.23 Evidence subject to the preservation requirement.

(a) *Biological evidence generally.* The evidence preservation requirement of section 3600A applies to “biological evidence,” which is defined in section 3600A(b). The covered evidence is sexual assault forensic examination kits under section 3600A(b)(1) and semen, blood, saliva, hair, skin tissue, or other identified biological material under section 3600A(b)(2).

(b) *Biological evidence under section 3600A(b)(2).* Biological evidence within the scope of section 3600A(b)(2) is identified biological material that may derive from a perpetrator of the offense, and hence might be capable of shedding light on the question of a defendant's guilt or innocence through DNA testing to determine whether the defendant is the source of the material. In greater detail, evidence within the scope of section 3600A(b)(2) encompasses the following:

(1) *Identified biological material.* Beyond sexual assault forensic examination kits, which are specially referenced in section 3600A(b)(1), section 3600A requires preservation only of evidence that is detected and identified as semen, blood, saliva, hair, skin tissue, or some other type of biological material. Section 3600A's preservation requirement does not apply to an item of evidence merely because it is known on theoretical grounds that physical things that have been in proximity to human beings almost invariably contain unidentified and imperceptible amounts of their organic matter.

(2) *Material that may derive from a perpetrator of the crime.* Biological evidence within the scope of section 3600A(b)(2) must constitute “biological material.” In the context of section 3600A, this term does not encompass all possible types of organic matter, but rather refers to organic matter that may derive from the body of a perpetrator of the crime, and hence might be capable of shedding light on a defendant's guilt or innocence by including or excluding the defendant as the source of its DNA.