At every crime scene, a suspect leaves some form of evidence behind and takes some for form of evidence with him. That’s according to the Locard’s Exchange Principle, the basis of forensic science. A piece of hair or a micro-fiber of carpet, though invisible to the naked eye, can become critical in court.

Though Timothy Masters was convicted on circumstantial evidence in the murder of Peggy Hettrick, there was plenty of physical evidence found at the scene, none of which was connected to him. From hair strands to fingerprints to DNA swabs, several pieces of evidence found on Hettick’s body, clothing and possessions could figure in to whether Masters gets a new trial.

That is, if those pieces of evidence can be located, and their chain of custody can be preserved well enough to remain legally relevant. Like much of the other evidence in dispute in Masters’ case, the physical trace evidence also finds itself at the heart of some controversy.

Although it is now 20 years old, if the evidence is well-preserved, modern science can put to good use, said Al Price, director of the Southern Institute of Forensic Sciences.

“Trace evidence is not only crucial, it has become expected,” he said. “We are under the ‘CSI Effect.’ ... Jurors expect police and crime scene people to find trace evidence.”

Price, of Greeley, worked in law enforcement for 30 years prior to retiring. He spent 23 years at the Weld County Sheriff’s Office, mostly assigned to homicide and sex crimes. Price does not have any involvement in the Master’s case, and he was not involved in the original investigation.

Price said that DNA analysis has become more widely accepted within the past few decades and that processing has become faster and more economical. DNA evidence was first used in the American court system in 1986 in a rape case in Florida and has become much more refined since then.

As long as evidence is collected and preserved property, it will last for years. Contrary to what is seen on TV shows, evidence is hardly ever stored in plastic bags, because that seals off the oxygen. The main factors that impact the durability of evidence are how it well it’s collected and preserved.

“The best evidence in the world is worthless if it’s not legally collected and if the chain of custody is not maintained,” Price said.

That may be little comfort to Masters’ attorneys. The defense team filed a motion last January to disqualify the Larimer County District Attorney’s Office, alleging it had illegally taken evidence to the Colorado Bureau of Investigation lab in Denver, without a court order, for DNA testing that would result in the destruction of the evidence. DNA testing had not been performed by Masters’ previous defense team, and Masters’ argued in the disqualification motion that the DA’s office attempted to “minimize any exculpatory evidence which might be obtained by the defense DNA testing.”

Whether the evidence would yield any results of interest remains to be seen, but it’s not out of the question. Mark Dale, the director of the Northeast Regional Forensics Institute at the University at Albany and author of The Crime Scene: How Forensic Science Works, said new technology can often advance old cases. He is also the former director of the New York State Police Laboratory System and the New York City Police Department Laboratory.

“I think it’s a very effective policy to take a look at old cases with new technology,” he said. “That’s always a good idea if you have the resources to do that. Particularly for homicide cases, I think that should be done, especially with unsolved cases.”

Dale added that while it isn’t common for evidence to go missing, it happens, either due to human error or it is sometimes destroyed as part of standard procedure.

“For most agencies, evidence for homicides is saved forever,” Dale said.

Again, Masters’ lawyers only wish this were the case. A request to the FBI for fingerprint photographs taken from Hettrick’s property yielded nothing but an affidavit from FBI headquarters in Quantico, Va. stating that the photos have been lost.

No one at the FBI’s Latent Print Operations Unit, according to the affidavit, “has any knowledge of where the original photographs and negatives might be.”

This is illustrative of the sorts of problems that can result from sloppy evidence handling.

“Any step in the total case, if not done properly, can seriously diminish the legal weight of a piece of evidence or can lead to exclusion of that evidence from being entered into court,” Dale said.