Thousands of cases investigated at Bexar County Crime Lab each year

‘The Investigation’: A look inside the Bexar Co. Crime Lab

Any cases dealing with serology, DNA, firearms and ballistics, gunshot residue, or drugs (controlled substances) would most likely be handled by a forensic scientist at the Bexar County Crime Lab.
Any cases dealing with serology, DNA, firearms and ballistics, gunshot residue, or drugs (controlled substances) would most likely be handled by a forensic scientist at the Bexar County Crime Lab.

SAN ANTONIOEditor’s note: “The Investigation” is a series of stories taking a closer look at forensic science and how it has evolved over the years to help law enforcement agencies solve crimes.

Crimes take place every day in San Antonio and as the population grows, so does the crime.

Any cases dealing with serology, DNA, firearms and ballistics, gunshot residue, or drugs (controlled substances) would most likely be handled by a forensic scientist at the Bexar County Crime Lab.

Every year thousands of cases are investigated at the lab making it one of the most efficient labs in the nation.

“For the second year in a row, we were awarded an award for our efficiency,” crime lab director Orin Dym said.

The staff of 30 was awarded the “Foresight Maximus Award” for operating at 90% or better efficiency. It’s an award given to only 15 labs in the nation.

In the past fiscal year (Oct. 1, 2019 - Sept. 30, 2020), more than 8,000 cases were investigated.

Case Records Per Investigation Area
DNA casework884
Drugs - controlled substances6,149
Firearms & Ballistics347
Gun Shot Residue259
Serology/Biology886
TOTAL8,525

Evidence Receiving

This department is where all evidence gets dropped off.

“It is the heart of the lab,” assistant crime lab director Erin Reat said.

The crime lab is not affiliated with law enforcement so all the evidence is dropped off in this area, logged and then given to a specific forensic scientist.

This process is done to make sure to limit the information that gets passed to the analyst.

“We don’t want biased information we want to be able to just make our calls with the data that we see,” Reat said.

After the analysis is complete it goes back to the law enforcement agency.

Serology/DNA analysis

This department works in tandem. First, a serology analysis is done to screen for biological evidence like blood, semen and saliva.

“These individuals (forensic scientists) screen evidence from sexual assault kits, any weapon that would have been used in an aggravated assault or homicide, clothing, bedding material, etc.,” Reat said.

If something is found then DNA analysis is done to either make a match on a potential suspect or exonerate that person of interest.

Drug Analysis

The majority of the cases examined at the Bexar County Crime Lab deal with drug analysis.

In this department, different controlled substances are investigated to determine what the drug is.

“80% of the work we do is controlled substance analysis,” Dym said.

This department also has the only two machines in the state that can help authorities determine the difference between marijuana or hemp. This came after the state passed a law legalizing hemp but making it hard for law enforcement to figure out whether the substance was marijuana or not.

“We take great pride that we were the first publicly funded crime lab in the state of Texas to be able to meet that requirement that we can answer that question generated from the new law,” Dym said. “And we’ve been very busy with it.”

Firearms, ballistics and primer gunshot residue

In this department forensic scientists take a closer look at the firearms used in crimes, examining markings on a bullet or casing, and determining if a bullet is fired from a certain gun.

Inside this area, is a room full of different types of firearms and a range to fire and analyze them when needed.

Recently one of the firearms examiners who testified in the Otis McKane trial was able to determine that the casings found at the scene all came from the same gun. This was determined without needing the gun which was never found in this case.

Future Growth

The Bexar County Crime Lab has outgrown their current space which is shared with the Bexar County Medical Examiner’s Office and are hoping to move to a bigger place in the next couple of years.

A bigger lab would accommodate the growing amount of cases that are being investigated and could also potentially allow the lab to expand to provide more services like toxicology.

“As we look to the future, it really is an issue of what are we not currently doing for the county that we can do,” Dym said. “We’re looking at what we can do for the county and how do we make the county a better place?”


About the Author:

Erica Hernandez is an Emmy award-winning journalist with more than 12 years of experience in the broadcast news business. Erica has covered a wide array of stories all over Central and South Texas. She's currently the court reporter.