Preservation of Evidence

Without biological evidence, none of the more than 350 exonerations based on DNA evidence would have been possible. 

Preservation of evidence laws require government agencies with guidelines for preserving biological evidence in criminal cases that have already been tried. More than half of the country has preservation of evidence statutes; Montana’s requires that evidence be maintained for a minimum of three years post-conviction.

DNA strand
(Photo from Science Magazine)

Preserving evidence is paramount to innocence work because if a case was tried prior to the advent of DNA testing or with an early or outdated form of DNA testing, having the preserved evidence would allow forensic analysts to conduct tests now. Also, if DNA testing was never conducted before the original trial even though advanced testing techniques that could identify the perpetrator were available, having the preserved evidence makes that possible.

Existing preservation of evidence statutes do have their shortcomings though: some limit the preservation of evidence to only specific crimes, and almost every state that has a law pertaining to the preservation of evidence allows for its premature disposal.

MTIP Legal Director, Caiti Carpenter, on the consequences of destroying evidence:

Robin Lovitt

In early 2000, Robin Lovitt was sentenced to death for the murder of the manager of a pool hall in Arlington, Virginia. At the time of Lovitt’s trial, the available type of DNA testing detected the victim’s blood on the murder weapon, which was a pair of scissors, but results were inconclusive as to whether Lovitt’s DNA was present. Lovitt sought post-conviction relief and hoped to conduct a new, more sophisticated form of DNA testing on the blood-stained scissors, but they had been illegally thrown out.

Lovitt, unable to effectively argue his innocence without testing the scissors, was facing the death penalty. Then-Virginia Governor Mark Warner ultimately commuted Lovitt’s sentence to life in prison without the possibility of parole because of the destroyed evidence. 

“The Commonwealth must ensure that every time this ultimate sanction is carried out, it is done fairly,” Warner said. “After a thorough review, it is my decision that Robin Lovitt should spend the rest of his life in prison with no eligibility for parole.”