Fairfax County police arrested a 19-year-old man Wednesday, Aug. 19, in connection with the stabbing death of Carmen Lizet Puch, a 42-year-old Reston mother found dead two days earlier at a Great Falls trailhead.

The department announced the arrest in an 8:18 a.m. post on X, Patch reported. Police said additional details would be released at a 1 p.m. news briefing led by Chief Kevin Davis at public safety headquarters. As of Wednesday morning, the department had not publicly disclosed the specific charges the suspect faces.

Sources told NBC Washington that the suspect and Puch were coworkers at Bitez, a restaurant in the Village Center at Dulles.

What happened Monday

Puch was found at 6:43 a.m. Monday, Aug. 17, in the gravel parking lot of Difficult Run Park in the 8800 block of Georgetown Pike, as we reported Tuesday. A jogger arriving for a morning run spotted her lying unconscious next to her burgundy 2011 Honda Civic and called police. Officers found trauma to her upper body and pronounced her dead at the scene.

Sources familiar with the investigation told NBC Washington that Puch was stabbed inside her vehicle. Investigators later towed the car. The parking lot has no security cameras.

At a briefing Monday, Aug. 17, Capt. Jason Chandler of the Fairfax County Police Department said there was "no immediate indication that this was a random act" and asked anyone who saw something near the park around 7 a.m. to contact police.

Detectives from the Major Crimes Bureau and Crime Scene Section took over the investigation.

'We're still taking it minute at a time'

Abdul Anwari, owner of Bitez, told NBC Washington on Wednesday that he and Puch's coworkers were stunned by her killing and the arrest of someone from their staff.

"I don't know if you can process something like this. It's not something you expect," Anwari said. "We're still taking it minute at a time."

Anwari said the restaurant has set up a GoFundMe for Puch's young daughter and that staff are also donating personally to the family.

Puch's family drove down from New Jersey after learning of her death to care for her daughter, according to NBC Washington.

The official cause and manner of death remain pending autopsy results from the Office of the Chief Medical Examiner.

Anyone with information about this case can contact the Fairfax County Police Major Crimes Bureau at 703-246-7800, option 2. Tips can also be submitted anonymously through Crime Solvers at 1-866-411-TIPS.