Authorities arrested two Baton Rouge people Monday — one on first-degree murder — after an argument involving them and others Thursday night escalated into shots fired and ended with the death of 19-year-old Erneisha Barnes, according to police.

Donnie Spencer, 27, is accused of firing the fatal shot that struck Barnes while she was sitting in the passenger seat of a car; Ashley Taylor, 30, is accused of firing into the same car without injuring either of the two women inside, police said.

Spencer fired several times from inside a Chevy Trailblazer into another vehicle within the 4800 block of Gus Young Avenue about 10:15 p.m. Thursday, police said. Barnes was taken to the hospital and later died.

Her mother, Patricia Bickham, said on Friday that Barnes was riding in the car while her best friend drove and they stopped at Ragusa’s Deli, a store on Gus Young Avenue frequented by a married man the friend had recently been seeing.

Bickham said she wasn’t sure exactly what happened next — how her daughter ended up dead — but knew the incident involved that man and possibly also his relatives or friends. Whatever the exact circumstances, Bickham said, her daughter apparently was caught in the crossfire during a dispute that didn’t directly concern her.

Police provided a similar account after arresting Spencer and Taylor on Monday, though they did not indicate whether the married man was present during the incident. 

Investigators believe an argument broke out between Taylor and the woman Barnes was with, who was possibly having an affair with Taylor’s husband, Coppola said. During the argument, Taylor fired at her opponent but missed.

Spencer — a “known associate of Taylor” — apparently was in the area when the argument broke out, drove by and from his vehicle fired at the same victim but struck Barnes instead, Coppola said.

He said investigators do not believe Barnes was the target but was “in the wrong place at the wrong time … and unfortunately as a result of that, we lost a young life.”

The U.S. Marshals Fugitive Task Force apprehended Spencer, of 3865 Beechwood Drive, in the Baton Rouge area on Monday after a Crime Stoppers tip on the case. He was booked into Parish Prison on first-degree murder and attempted first-degree murder.

While authorities escorted him from the state police Violent Crimes Unit into a vehicle that would transport him to prison Monday afternoon, Spencer shook his head slowly while telling reporters repeatedly: “I’m innocent.”

Taylor, of 2577 Bartlett St., turned herself in and was also arrested Monday on attempted second-degree murder and illegal use of a weapon.

Coppola attributed the quick arrests of both suspects to witness accounts and information from the public. “The community is a great asset we have,” he said. “It’s a shame we have lost the lives we have lost, but we are appreciative of the community stepping forward to make such a quick arrest in this case.”

Follow Lea Skene on Twitter, @lea_skene.