Arlington cold case murder suspect IDed with drop of blood, discarded fork

ARLINGTON, Texas - An Arlington homicide detective became emotional when sharing new details about what led to the arrest of a North Texas real estate agent for a 2012 cold case murder.

Arlington Cold Case Murder

What we know:

Mayra Valasquez was arrested on July 16 and charged with capital murder for the death of 32-year-old Irasema Chavez in January 2012.

Chavez was found dead in her apartment near South Collins Street and East Timber View Lane. She had been stabbed more than 100 times.

In 2012, Arlington police shared photos from a security camera that showed someone in baggy clothing entering Chavez’s apartment on the night before the murder, but they were never able to identify a suspect.

What's new:

During a news conference on Wednesday, Arlington police revealed that Valasquez was linked to the crime through genealogy technology.

They said Chavez’s TV had been stolen from her apartment and there was a droplet of blood found on the TV stand. That droplet contained the DNA of a Hispanic female who was not the victim.

In 2024, Arlington Police Department Det. Tracey Dixon began working with the FBI Dallas Field Office on the case using the FBI’s Investigative Genetic Genealogy program.

A DNA match from one of Valesquez’s relatives and then DNA on a discarded plastic fork helped them identify her as the suspect.

Police said they also have valuable cellphone data that will be used as evidence in court. 

What they're saying:

The lead detective fought back tears on Wednesday when asked about sharing the news of Valasquez’s arrest with Chavez’s family.

"Telling the family… that’s why," Det. Tracey Dixon said. "Being able to share that with a family is why we do this work. And they were very grateful."

Arlington Police Chief Al Jones said the genetic technology used to crack the case has been a game change for law enforcement.

"It helped provide answers to families and communities who have waited years to receive," he said. 

FBI Dallas Special Agent in Charge Joe Rothrock said it’s a resource-intensive process.

"It starts with an unknown DNA sample recovered from a scene. That sample is then submitted to a publicly accessible genealogy service to identify potential relatives of the unknown DNA profile. Investigators then begin the process of constructing a family tree of individuals identified as potential relatives," he explained. "FBI personnel review individuals within the family tree who could potentially be the suspect, compare them to information such as witness accounts, location, and timing of the crime to identify a likely suspect. Only then do we seek a comparison of DNA between the potential suspect and the unknown DNA from the crime scene."

Since 2018, the FBI has used the process to help solve nearly 250 cases across 30 states. This is now the second case in Arlington.

"I am extremely proud of the work that our officers and our crime scene investigators did on this case. They showed tenacity, dedication and they never gave up. I am grateful for the FBI for their continued partnership, and I'm most thankful that we're able to tell the family of Ms. Chavez that we've made arrest in this case," Chief Jones said.

What we don't know:

The motive for the murder remains unclear.

Police said Valasquez and Chavez were close friends. According to the affidavit, detectives received a tip after the murder that Valesquez’s husband may have been jealous of the two women’s close relationship.

Valasquez was interviewed at the time but never tied to the case, police said.

What you can do:

Police said they are not looking for any other suspects in the case, but they are still investigating the motive.

Anyone with details is urged to contact them.

ArlingtonCrime and Public Safety