A Pennsylvania man was arrested Sunday in last week’s killing of a teen during a road rage incident at a merge that authorities said turned into a high speed “cat-and-mouse game.”

David Desper, 28, of Delaware County in Pennsylvania, was charged with first degree murder in the death of 18-year-old Bianca Roberson after turning himself in to police.

“This was a savage, senseless, brutal act,” Chester County District Attorney Thomas Hogan said.

He said Desper became enraged Wednesday afternoon as he and the teen, who had just graduated high school, jockeyed for position on a two-lane West Goshen road that merges into one lane.

“This defendant wasn’t happy with the way it was going and pulled out a gun and killed this young woman,” Hogan said.

The DA said detectives seized the red Chevy pickup truck that Desper was driving and the gun he used to kill the Roberson.

Hogan said the gun was a .40-caliber Smith & Wesson semi-automatic that Desper had legally purchased in 2015.

On Saturday, West Goshen Township police released photos of Desper’s vehicle.

They also released a sketch of the suspect on Twitter Friday.

Police came up with the sketch after speaking to a witness who was near the suspect's pick-up truck around the time of the shooting, Fox 29 Philadelphia reported.

Highway cameras show Roberson and the pickup driver having some sort of altercation before the shooting, WPVI-TV reported.

Roberson was shot in the head and died instantly. Her car veered off the road and was later found in a ditch. The shooter fled, driving partly along the shoulder of the highway until exiting the road.

Roberson graduated in June from Bayard Rustin High School in West Chester. She was headed to Jacksonville University in Florida in the fall.

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The Associated Press contributed to this report.