The 19-year-old man arrested in the fatal stabbing of a woman at Difficult Run Park in Great Falls has been charged with second-degree murder, and Fairfax County police say the two worked together and were in an intimate relationship.

Alexis Antonio Cedillos-Campos was charged Wednesday, Aug. 19, 2026, in the killing of Carmen Lizet Puch, 42, of Reston. As we reported earlier Wednesday, Cedillos-Campos was taken into custody in Maryland with help from the U.S. Marshals Service and Prince George's County police.

Police said both worked at Bitez restaurant in Herndon's Village Center at Dulles. According to Fox 5 DC, investigators allege Cedillos-Campos left the restaurant in the early morning hours Monday, Aug. 17, 2026, carrying a large fixed-blade knife, latex gloves and a water bottle he had emptied and filled with gasoline siphoned from his motorcycle.

Police allege the stabbing occurred in the Difficult Run Park parking area in the 8800 block of Georgetown Pike. According to NBC4 Washington sources, Cedillos-Campos repeatedly stabbed Puch inside her dark red 2011 Honda Civic, poured gasoline on her and unsuccessfully tried to set her on fire.

A person arriving for a morning run found Puch at approximately 6:43 a.m. She was pronounced dead at the scene.

McLean District Station officers were the first to respond, and Georgetown Pike was closed in both directions at Old Dominion Drive during the investigation.

Fairfax County police said Cedillos-Campos offered a full confession to homicide detectives. Investigators identified him within 48 hours of Puch's death.

Abdul Anwari, owner of Bitez, told NBC4 that he and Puch's coworkers were stunned. "I don't know if you can process something like this. It's not something you expect," Anwari said.

Puch was the mother of a 3-year-old daughter. Friends told NBC4 her family drove down from New Jersey to care for the child. Anwari said a GoFundMe has been set up for the family and that he and coworkers are personally donating to support Puch's daughter.

The parking lot where Puch was found has no security cameras, according to NBC4 sources. It connects to several trails, including the Difficult Run Stream Valley Trail leading to Great Falls Park.

Police Chief Kevin Davis was scheduled to brief reporters at 1 p.m. Wednesday, Aug. 19, at public safety headquarters. Anyone with information is asked to contact Fairfax County police at 1-866-411-8477 or submit a tip at fairfaxcrimesolvers.org.