Local criminologists weigh-in on the impacts of DNA evidence

One of the biggest aspects surrounding the Chris Tapp case being the role DNA evidence played (and didn’t play) into his conviction, it had us wondering just how impactful DNA evidence has been over the years in related cases.

So, we went to Idaho State University to speak with criminology professor Deirdre Caputo-Levine who told us, yes, DNA testing is in fact more reliable than any other form of analysis (such and finger printing and bite mark analysis), but there are still a number of factors that play into whether or not DNA should be used.

It starts with what she calls the “CSI Effect”.

“People always think there is going to be DNA,” Caputo-Levine said. “They always think there is going to be something left behind. Unfortunately, that doesn’t happen a lot of the time.”

She said the world of DNA has little to do with what you see on those primetime crime scene shows.

That’s just Hollywood being Hollywood.

“Sometimes the DNA is degraded, sometimes you get samples that are mixed, and that’s when it gets really difficult,” she added.

She said, although DNA testing has been trusted and is reliable, there are issues, the “grey area” that criminologists have to contend with, such as contamination. And, at the end of the day, DNA samples don’t replace good police work.

“Unless the police work is done perfectly, all of the T’s are crossed and the I’s are dotted, then there’s the possibility that you might have that evidence that might be beautiful evidence, but it’s not going to be useable.”

She said, in the state of Idaho, no one is guaranteed that DNA will be tested. You have to appeal for a post-conviction analysis, and then the court will determine whether the test results will have the “scientific potential” to show it’s more probable than not that the petitionary is innocent.

Compounded on top of that, there’s no state law requiring that evidence be retained. Meaning, key evidence could be lost.

Now, let’s say someone petitioning for that DNA analysis finally goes through the long appeals process successfully. Now, you have to think about sending that sample away to the lab, which are usually always back-logged for months on end. This introduces another potential for contamination at some point along the way.

In fact, Caputo-Levine said as of 2016, there are still 1,116 sexual assault kits still waiting to be tested at these labs because of the back-log.

That’s why, in cases such as O.J. Simpson and Amanda Knox, submitting DNA as evidence wasn’t just a cut-and-dry answer to either convict or free a suspect.

She said the very first case known in the United States to use DNA testing where it ended up leading to a conviction was back in 1987 in Orange County, Florida.

In most recent developments, familial testing is done in the UK, but it’s controversial here in the United States.

That’s where DNA samples could be matched with relatives who are already in the system in order to track-down the suspect or even a missing person.

However, she said there are a lot of questions surrounding Fourth Amendment rights with this method.

So, while DNA testing is the strongest, most reliable form of analysis we have today, it still has its flaws, with tons of minor details that people often don’t realize could impact the success of submitting DNA as evidence.