DALLAS – A Dallas Police investigation into a double homicide continues after the suspected gunman was found dead from a self-inflicted gunshot wound in Mesquite, authorities announced.

Double murder-suicide investigation

What we know:

Dallas officers responded to a shooting call in the 15800 block of El Estado Drive in Far North Dallas at 2:40 p.m. on December 11, 2025. The preliminary investigation determined that two people had been shot.

The victims were identified as 24-year-old Arlina Sander, who died at the scene, and 27-year-old Darvilease Washington, who was taken to a local hospital where he later died.

Detectives quickly identified a possible suspect and a suspect vehicle registered in Mesquite. As Dallas detectives prepared an arrest warrant, they were notified by the Mesquite Police Department about a shooting in that city.

Suspect found dead in Mesquite

The suspect in the El Estado homicides was found dead in the 1000 block of Craig Drive in Mesquite, having suffered an apparent self-inflicted gunshot wound. The suspect’s vehicle was found in the driveway.

The Dallas County Medical Examiner has identified the man as 44-year-old Jonathan Lakill Mantoy Jones. His time of death was just after 5 p.m., according to the M.E. report.

What we don’t know:

The motives and circumstances surrounding the offense are still under investigation. 

Dallas Police ask anyone with information to contact Detective Paul Johnson at 469-271-6328 or via email at paul.johnson@dallaspolice.gov. 

The BMW Dallas Marathon is in full swing this weekend. Events started Friday night and will run through Sunday.

Saturday morning included a 10K, 5K, and the kids’ 100-meter dash, but Sunday is the big day so many runners have been training for.  

From young runners to older runners, thousands participated in Saturday’s events, including one of Santa’s elves.

“Santa made me work today,” said John Schmidt, who participated in the 5K dressed as Santa’s finest.

Myrna Besley came from Colorado to jog the BMW Dallas Marathon 5K on Saturday morning, pushing her grandson along the way.

“My daughter is a runner, we do this to go along with her, she’s way ahead of us, and she’ll be running in the marathon tomorrow,” Besley said.

Teachers Caroline Menzia and Emma Gayle took a break from the classroom to hit the pavement. 

“We work hard every day in our job, and I don’t know, we wanted to push ourselves outside of our work, to do something for us that we can accomplish,” said Menzia.

Organizers said while a lot goes into planning this event, it’s important for runners to enjoy the journey it’s taken to get here.

“Have some fun, smile, it’s hard, getting to the finish line is not easy,” Jason Schuchard, president of the BMW Dallas Marathon, said. “But just relax, trust your training, and just remember to smile.”

If you’re one of the thousands of runners running on Sunday, organizers said to arrive early, stay hydrated, and stay warm.  

“Come early, park early, make yourself comfortable, you don’t want to stress out,” said Dr. Logan Sherman, chairman of the BMW Dallas Marathon. “It’s going to be cold, so bundle up and any clothes or any items you want to discard before you get to the start, please know that you can discard it on the side of the corral right before you’re about to take off.”

There will be many road closures in Downtown Dallas on Sunday from 7 a.m. to 4 p.m. For more information, visit: https://dallasmarathon.com/.