Police in Arlington, Texas say they finally know who killed Irasema Chavez. It took 14 years and one drop of blood.

Officers arrested Mayra Velasquez, 42, on July 17. She worked as a real estate agent in the Dallas area. Cops charged her with capital murder. That is the most serious murder charge in Texas. It can mean life in prison without parole, or even the death penalty.

Chavez was 32 years old. Someone stabbed her more than 100 times inside her Arlington apartment. Her niece found her body on January 20, 2012. The front door showed no signs of a break-in. Because of that, police believed Chavez knew her killer.

Detectives found one key clue right away. A single drop of blood sat on a TV stand in the bedroom. It did not belong to Chavez. Police ran the DNA through CODIS, a national police DNA database. They got no match. Lab workers could only say the blood came from a Hispanic woman. The case went cold for years.

In 2016, a lab used the DNA to guess what the killer might look like. That sketch still did not lead to an arrest.

Everything changed in November 2024. Arlington police asked the FBI for help. The FBI runs a program called Investigative Genetic Genealogy. Here is how it works in plain terms. Scientists compare crime scene DNA to family tree websites. These are the same sites people use to find lost relatives. They find people who share small bits of DNA with the suspect. Then they build a family tree. That tree helps them narrow the list down to one person. This method has helped solve hundreds of cold cases across the country.

By early 2026, the FBI gave Arlington police a name. That name was Mayra Velasquez. Police say she was a close friend of Chavez and had visited her apartment before. She lived only a few miles from the crime scene.

Detectives still needed fresh DNA from Velasquez to be sure. In May 2026, undercover officers followed her to a restaurant. After she left, they picked up the fork, plate, and cup she used. A lab tested that DNA. It matched the blood found on the TV stand back in 2012.

Police arrested Velasquez on July 17 in the nearby city of Hurst. She now sits in the Tarrant County Jail with no bond. That means she cannot pay money to get out while she waits for trial.

Arlington police have not said why they think Velasquez killed her friend. They have not shared a motive. Police and the FBI set a joint news conference for July 22 to share more on how the case broke open.

Detective Tracey Dixon worked the case. She talked about telling the Chavez family the news after 14 years of waiting. "Being able to share that with the family is why we do this," Dixon said.

This case matters far beyond Arlington. DNA testing keeps getting better and cheaper every year. Genetic genealogy did not even exist as a police tool a decade ago. A drop of blood sat useless in a police file for over a decade. Now it helped crack the case wide open. Families across Texas lost loved ones in old unsolved killings. Many of them are watching cases like this one. It gives them hope. New science may someday name their family member's killer too.

Her case now moves into the Tarrant County court system. It is not yet clear when she will first appear before a judge. El Tejano will follow the case as it moves forward.