SWAT has converged on a suspected murderer after a standoff at a Lancaster gas station this afternoon.

The suspect has been apprehended, but it's not clear if shots were fired. The name of the man and his condition were not known.

Dallas County Sheriff's Department's G. Forester said a traffic officer tried to pull the man over shortly after 1 p.m. on Wednesday because he was weaving and speeding on the road.

He said the driver didn’t stop immediately, pulling onto a service road and then into the Shell gas station at the corner of Interstate 35 and Pleasant Run Road.

“As the officers approached the vehicle, they saw that the person in the car had a gun in his right hand with the gun pointed to his head and a cell phone in his left hand,” Forester said. “They immediately stepped back and advised dispatch that they had a subject with a gun.”

Authorities then began evacuating people from the gas station and surrounding businesses.

He said tactical teams from the sheriff’s department and the constable’s office were on scene. A negotiator tried to talk to the man, but he had did not have any information how those discussions were going.

Dozens of onlookers gathered along the southbound I35E service road for hours as the standoff unfolded. At about 5:45 p.m., tactical officers could be seen moving in past the Shell station gas pumps on the white four-door vehicle, with guns drawn and shields in hand.

A flash was seen and a loud blast reverberated throughout the area before officers opened the driver's side door and dragged him out.