The Tennessee Bureau of Investigation handles some of Tennessee's most notorious crimes -- the ones that make news far and wide.
It also takes on a lot more than big cases using very sophisticated equipment in their arsenal.
"Single capillary electrolytic instrument," Chuck Hardy, a member with the DNA unit, named one piece of the equipment in his department.
DNA identifiers, chemicals that can detect human versus animal blood, and plenty of magnifying equipment surround the DNA labs in the Nashville TBI offices. Constantly, that equipment is updated.
"When you have a sample that you run DNA on, it takes 30 minutes..." Hardy said about the DNA identifier, colloquially called a "genetic analyzer."
Hardy said that specific piece of equipment is a lot faster than the two weeks it used to take when he started a dozen years ago. Back then, he would need many drops of blood. Now, with just a simple touch of a finger, these scientists can find out blood types and whether it is a victim's or suspect's with near-perfect accuracy.
"So my question sample from a towel might hit on a convicted offender in Washington State, or an arrested sample in Milwaukee," Hardy said.
However, the DNA unit is not the only place with these new updates at their disposal -- in the firearms unit, special agents prove a weapon, or traces of one, can be just as important as blood as far as clues go. Special agent Steve Scott tests some of the newest guns available.
"Ammunition changes on a quarterly basis because manufacturers want to keep up with the newest, hottest thing out there in the market," said Scott.
He can compare bullets fired here with a state-of-the-art "duel image microscope." The equipment has only been around for a few years, but it has pinpoint accuracy.
The information goes into another database called NBIS -- a weapon that has been at their disposal for only a few years.
"It's a way to put digital images of the cartridge cases from crimes and guns that are recovered," Scott added.
Hundreds of thousands of guns and bullets can be sorted in a few hours with NBIS. Years ago, Scott said it would take days or longer before they could find a match.
He said if investigators can identify a bullet, they could potentially tell whose gun it came from.
"In all of forensic science, we compare something that's unknown to something that is known -- has a known source," Scott said.
Not far away from the firearms lab, the narcotics division of the TBI also has their hands full -- constantly testing drugs using some new equipment in their possession.
"With our interstate system, we're able to acquire large quantities of marijuana," narcotics expert Glen Glenn said.
With the surge of synthetic and illegal prescription drugs coming onto the streets, Glenn's unit has to stay ahead of the trends.
Using infrared technology, only in use for a few months, a computer can tell the chemical compound of a drug.
"Trying to find an analytical standard,we can compare the substance to a known standard," Glenn said.
It can show how dangerous an unknown drug could be to a person.
"We can use that to a confirmation of what that substance is," Glenn added.
With a lot of research, testing, and comparing, these scientific crime-fighters play an important part at the TBI, and they are doing their work faster than ever before.
"We're able to push stuff through. The output is much higher. Backlog is able to be reduced a lot more," Hardy said.
According to TBI, the backlog of cases went from a year's wait to as low as eight weeks, thanks in part to this new equipment.