Prince George’s County police homicide detectives have arrested two more suspects who they believe were involved in the fatal shooting of a Howard University freshman in Mount Rainier last week.

Lorenzo Carlton, 21, of Silver Spring, and Michael Jordan, 18, of Northeast D.C., both are charged with first-degree murder in the Oct. 25 shooting of 24-year-old Alonzo James Guyton. Guyton was shot and killed as he was walking to a friend’s house in the 4200 block of Kaywood Drive in what police now say was a robbery.

Detectives had already charged William Knight, 20, of Northeast D.C. in connection with the shooting.

Police officials and law enforcement sources said the men had set out to rob someone early in the morning on Oct. 25, choosing the apartment complex where Guyton was headed because it is near the D.C.-Prince George’s border and has limited parking, forcing visitors to park some distance away and walk there. They attacked Guyton, a stranger to them, near the apartments, authorities said.

Police said Carlton, who was on probation for an unauthorized use of a motor vehicle conviction, was arrested Wednesday and is in the Prince George’s jail. Jordan was already being held in the D.C. jail on an unrelated charge and is now awaiting extradition to Maryland, police said.