Ashton Briscoe was charged with first-degree murder in the Dec. 28 killing of Kerrice Lewis, 23, who was found in the trunk of a burning car in the 800 block of Adrian Street SE. She was among three people killed that day in the District and Maryland, killings police believe are linked. (N/A/Prince George’s County State’s Attorney’s Office)

Two friends who were killed in the District on a single day in December were shot with the same gun and in the same alley in Southeast Washington, according to newly released records and court testimony on Monday.

Armani Nico Coles, 27, was found the evening of Dec. 28 after his body was shoved out of a car on a street near the Anacostia Freeway in Capitol Heights, Md. Kerrice Lewis, 23, was found dead an hour later in the trunk of a burning blue Lexus, in an alley about three miles away. She had been shot 15 times.

Police said Lewis and Coles, a custodian in the D.C. school system, were killed by associates of a man who had been fatally shot hours earlier outside a convenience store in Northeast Washington. The suspect in the killing outside the store was friends with Lewis and Coles, court papers say.

But even with arrests in all three killings, authorities have not yet discerned a clear motive. Court documents recount several possibilities based on tips, none of them corroborated. They include robbery, a credit card scheme or an old gambling debt.

“It was a horrible crime,” said D.C. Police Chief Peter Newsham, declining to elaborate on a possible motive and urging anyone with information to come forward and help.

Police on Saturday charged Ashton Briscoe, 23, of Northeast, with first-degree murder in connection with Lewis’s death. He was ordered detained Monday during his initial appearance in D.C. Superior Court.

Assistant U.S. Attorney Thomas Saunders said in court that Briscoe’s role in the killing was “to serve as a lookout for witnesses and law enforcement.”

Court documents say Briscoe first denied to police that he had been at the scene in the alley, then admitted he accompanied a friend there, but said he did not participate in the killings.

His court-appointed attorney, Robert Hairston, said in court that his client did drive a vehicle to the alley where Lewis and Coles were killed, but “there is no proof my client knew what was going to happen before it happened.”

Police said the events on Dec. 28 began about 11:20 a.m. when Ranzay Green, 23, of Northeast, was shot in a 7-Eleven parking lot on Eastern Avenue. Police charged Dennis Whitaker, a 23-year-old local rapper known as “Jugga Knott,” with first-degree murder.

About 6:20 p.m. the same day, police in Prince George’s County said Coles was found along Eastern Avenue after having been pushed out of a car about one mile from the 7-Eleven. He had been shot. Police later charged Malique Lewis, 20, with first-degree murder. It is unclear whether the Lewises are related.

About an hour later, police said Kerrice Lewis was found shot and left inside the trunk of the Lexus that had been set on fire in an alley off the 800 block of Adrian Street SE, about 2½ miles from Eastern Avenue.

Police said Malique Lewis and Briscoe were friends with Green, the man killed at the 7-Eleven. They said Whitaker, charged with killing Green, was friends with Coles and Kerrice Lewis.

According to the arrest affidavit filed in connection with Briscoe’s case, he told police that at the alley he heard gunshots and saw Malique Lewis with a .45-caliber gun moments later. He told police that Lewis told him Coles had resisted — “he bucked, so I had to let him go,” according to the arrest affidavit. The Prince George’s County public defender’s office, which is representing Malique Lewis, declined to comment.

Police said that on Jan. 2 they found the second vehicle that had been driven to the alley where the killings occurred. Inside they found a McDonald’s receipt from Dec. 29, a day after the shootings, and then matched surveillance video from the restaurant showing Malique Lewis in the driver’s seat, police said.

Lynh Bui contributed to this report.