>> My name is Brandon McCollum and I'm a forensic DNA examiner
for the Federal Bureau of Investigation.
So when I'm handed a specific case, I need to look at the evidence that's submitted the case
from a DNA perspective and I determine what evidence I'm going
to test and how it's going to be tested.
Once we generate results from those tests, I'll then interpret that information that we gathered
from the testing procedures and then I provide that information to investigators in the field.
If necessary at any point I then have to testify in the court of law to the results
that I've obtained through the DNA testing at the FBI.
So with it being at the FBI I do see cases literally from all around the world,
and those types of cases span counterterrorism cases, counterintelligence casework.
Also the typical violent crimes that you think of, like murders, robberies, sexual assaults,
things like that, but we also do do missing persons investigations
and paternity testing as well.
One of those is a cold case that was cold for about 30 years
in California that I was involved in.
Without giving too many details, basically a 14-year-old girl was walking home
from school one day and she was brutally murdered and stabbed upwards of 50 times,
and there was no real evidence in the case.
DNA testing technology didn't exist at that time 30 years ago, no subject,
and so the case literally went cold.
And a cold case team sent in some evidence for some DNA testing and what we had found was,
remarkably, is that during that attack the subject also had bled himself.
So what we were able to obtain was an unknown male DNA profile on the victim's purse
that was hanging in a tree from the location where she was murdered,
and the blood reasonably was going to belong to the perpetrator of that crime.
We were able to put that unknown male DNA profile on the victim's purse
into a DNA database and it hit to a previously convicted offender, thereby basically solving
that case that went cold for 30 years.