“And it’s also really a hope for loved ones who are waiting for their cases to be solved after all those years,” Alex del Carmen said.
ARLINGTON, Texas — Court documents reveal who Arlington police believe is captured in surveillance video and responsible for a brutal 2012 stabbing that remained unsolved for more than a decade.
On July 17, Arlington Police Detective T. Dixon arrested 42-year-old Mayra Velasquez, saying investigators connected her to the crime through the department’s Genetic Genealogy Program.
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Alex Del Carmen, a law enforcement expert unconnected to the investigation, said advances in DNA technology are giving investigators new opportunities to solve long-standing cold cases.
“All of a sudden, you have a DNA match up,” Del Carmen said. “And it’s also really a hope for loved ones, who are waiting for their cases to be solved after all those years.”
According to court documents, officers found 32-year-old Irasema Chavez dead inside her South Collins Street apartment on Jan. 19, 2012. Homicide detectives say she had been stabbed more than 100 times.
Among the evidence collected at the scene was a small drop of blood investigators believed belonged to the killer. That DNA evidence was preserved and later reanalyzed as technology advanced. Dixon said, based on his training and 22 years of law enforcement experience, he knows that when a person stabs another person in the manner that Velasquez allegedly did in this case, the attacker will often receive cuts to their own hands and body, which will often cause them to leave their own blood evidence at the crime scene.
Dixon wrote in his arrest warrant affidavit that he believes the bedroom television stand blood droplet, which was fresh and still glistening, was left there as a result of Velasquez getting cut while murdering the decedent.
Court documents state investigators eventually determined the blood belonged to a Hispanic woman. Detectives then conducted surveillance on Velasquez. Undercover officers followed her to a local restaurant. After watching her eat lunch with friends, the undercover officers collected two plastic forks she had used and submitted them for DNA testing along with her plate and cup.
According to the arrest affidavit, DNA recovered from one of the forks matched the DNA profile developed from the blood found on a bedroom television stand inside Chavez’s apartment.
Velasquez identifies herself on Facebook as a realtor with a local real estate company.
Court records show Arlington police arrested Velasquez on May 13 during a traffic stop on a capital murder charge. Family members declined to comment when contacted by WFAA.
The arrest comes months after another high-profile cold case investigation by Arlington police. In November 2025, investigators arrested Janie Perkins in connection with a 1991 murder after reexamining old evidence. However, a Tarrant County grand jury declined to indict Perkins in March, ending that prosecution.
Del Carmen said he believes advances in DNA technology and the preservation of evidence will continue to help investigators solve decades-old crimes.
“I do foresee that many, many cases are going to be solved in the future because that evidence has been preserved since the time of the crime,” he said.