CHAIN OF CUSTODY ANALYSIS FOR PHYSICAL EVIDENCE
From MN Bench Book - Trial Procedures & Practices for Judges
A CHAIN OF CUSTODY OBJECTION IS ANALYZED PURSUANT TO RULE OF EVIDENCE 901- AUTHENTICATION - TO DETERMINE ADMISSIBILITY OF THE ITEM OR A TEST ON THE ITEM
THE BASIC RULE IS:
1. The requirement of authentication or identification as a condition precedent to admissibility is satisfied by evidence sufficient to support a finding that the matter in question is what its proponent claims.
2. All possibility of alteration, substitution, or change of condition need not be eliminated in laying a chain of custody foundation. In the absence of any indication of substitution, alteration or other form of tampering, reasonable probative measures are sufficient. 
3. Gaps in the chain of custody normally go to the weight of the evidence rather than its admissibility.
4. Rule 104 (a) allows judges to base the admissibility of physical evidence on items such as "a chain of custody log" rather than requiring every person in the chain to testify. The rules of evidence don’t apply to these admissibility questions. 
THE FOLLOWING FACTORS SHOULD BE CONSIDERED IN DETERMINING THE DEGREE, IF ANY, OF DETAIL NEEDED IN REGARD TO THE CHAIN OF CUSTODY OF AN ITEM IN DECIDING THE ADMISSIBILITY OF THE ITEM
- 1. ITEM
- What is it? object/ original/ copy/ picture
- 2. PURPOSE; WHAT IS THE ITEM BEING OFFERED FOR?
- The purpose the item is being offered for will determine the level of authentication required. If the item is being offered to establish the existence and/or possession of the item, a lower level of authentication is required than the level of authentication required when the condition of the item at a specified time or the result of a test on the item is in issue. If the result of test performed on the item is in issue a detailed chain of custody may be necessary even if item is difficult to contaminate/ adulterate or alter.
- 3. POINT IN TIME CHAIN OF CUSTODY RELEVANT TO?
- SEIZURE TO TIME OF FORENSIC EXAMINATION/ TEST
- SEIZURE TO TRIAL
- 4. FUNGIBILITY; HOW EASY OR DIFFICULT IS IT TO ALTER, ADULTERATE OR CONTAMINATE THE ITEM
- The greater the fungibility of the item, the more detailed chain of custody may be required.
- e.g. a bag of green leafy substance vs. one of a kind piece of sculpture used as a weapon.
- 5. STORAGE METHOD
- The storage method and the degree of limitation of access to the item may or not may not be relevant depending on the purpose for which the item is being offered.
- How was the item stored and what kind of access was available between seizure and test or presentation in court?
- What type of physical security was the object subject to between seizure and presentation for test or presentation in court?
- Who had access to item from time of seizure to being offered?
- 6. WHO CAN LAY FOUNDATION RE: WHAT ITEM IS, ACQUISITION, STORAGE, RETENTION, SECURITY AND CONDITION AT RELEVANT TIMES?
- 7. ADMISSIBILITY VS WEIGHT
- Admissibility -fairly low standard and determined by judge
- Weight -- determined by jury
- Schram v. Commissioner of Public Safety,359 N.W.2d 632 (Minn. Ct. App. 1984). Implied Consent license revocation challenge in a judicial review. Blood sample obtained per an Implied Consent request for such by a police officer.
In Schram, the officer who was involved in obtaining the blood sample testified, and the BCA person who received and analyzed the sample testified, but the person who physically transported the sample did not testify. The trial court dismissed the case for lack of chain of custody. The Court of Appeals reversed, stating: “…ALL POSSIBILITY OF ALTERATION, SUBSTITUTION, OR CHANGE OF CONDITION NEED NOT BE ELIMINATED IN LAYING A CHAIN OF CUSTODY FOUNDATION. IN THE ABSENCE OF ANY INDICATION OF SUBSTITUTION, ALTERATION OR OTHER FORM OF TAMPERING, REASONABLE PROBATIVE MEASURES ARE SUFFICIENT.”
- Melendez-Diaz v. Massachusetts, 129 S. Ct. 2527
- Re: Chain of Custody
"we do not hold, and it is not the case, that anyone whose testimony may be relevant in establishing the chain of custody, authenticity of the sample, or accuracy of the testing device, must appear in person as part of the prosecution's case. While the dissent is correct that “[i]t is the obligation of the prosecution to establish the chain of custody,” post, at 2546, this does not mean that everyone who laid hands on the evidence must be called. As stated in the dissent's own quotation, ibid., from United States v. Lott, 854 F.2d 244, 250 (C.A.7 1988), “gaps in the chain [of custody] normally go to the weight of the evidence rather than its admissibility." It is up to the prosecution to decide what steps in the chain of custody are so crucial as to require evidence; but what testimony is introduced must (if the defendant objects) be introduced live. Additionally, documents prepared in the regular course of equipment maintenance may well qualify as nontestimonial records. See infra, at 2550 - 2551, 2552.
- Minn. R. Evid. Rule 901. Requirement of Authentication or Identification
- Schram v. Commissioner of Public Safety, 359 N.W.2d 632 (Minn. Ct. App. 1984).
- United States v. Lott, 854 F.2d 244, (C.A.7 1988).
- But see Melendez-Diaz v. Massachusetts 129 S. Ct. 2527