Authorities have charged a suspect in the fatal shooting of a motorist on a Plymouth highway with second-degree murder, according to charges unsealed Friday evening by a Hennepin County judge.

Police Chief Erik Fadden announced an arrest in the case Thursday and on Friday provided more details about the events of July 6, when gunfire from a Chevy Suburban killed 56-year-old Jay Boughton on Hwy. 169 near the Rockford Road exit.

According to charges unsealed late Friday, authorities arrested 33-year-old Jamal L. Smith on Aug. 24 in Decatur, Ill., about 180 miles south of his hometown of Chicago. He remains jailed there pending extradition to Hennepin County.

Before the unsealing, Fadden said the sealing was necessary because Boughton's death remains under "open and active investigation."

Fadden said Friday that the Suburban was in the left-hand lane and trailing Boughton's vehicle in the right-hand lane. The Suburban's right-turn signal light came on "as if to assume [the defendant] wants to merge into the right lane," Fadden said.

According to the charges, Boughton's teenage son, who was in the car with him as they returned from a baseball game, told police that when the suspect's SUV pulled up, his father "gestured" at its driver. Within 10 seconds, the son said, the driver's side passenger window was shattered by a bullet and his father slumped over.

After finding surveillance video of the Suburban, police were able to track it to a veterinary hospital, whose own surveillance video showed the driver wearing a white shirt with a strap across his chest.

On July 23, a towing company told police that it had the suspect vehicle in its impound lot. Investigators found that the vehicle had been rented by a woman in April 2021 and recently was reported stolen when it was not returned. Surveillance video from a gas station near the home of the woman showed the suspect in the vehicle.

Police also found a Facebook Live video on Smith's Facebook page of him that resembled the suspect in surveillance video.

On Thursday, Boughton's brother-in-law, Stephen Robinson, told WCCO Radio's Susie Jones that authorities told the family that the Suburban's driver wanted to move into the right lane, but Boughton gave a shrug toward the Suburban before being shot.

Fadden has said since days after the encounter that the shooting was over something as minor as a lane change.

Fadden also said Friday that "we know there was more than one person in that vehicle" with the defendant, but he declined to say how many. According to the charges, two other people are under investigation, but no additional arrests have been announced.

Staff writer Chao Xiong contributed to this report.