Prince George’s County police have charged a D.C. man in connection with Tuesday’s fatal shooting of a Howard University freshman in Mount Rainier, authorities said. `

William Knight, 20, is charged with first-degree murder in the slaying of 24-year-old Alonzo James Guyton, a freshman music major who was found just after midnight fatally wounded in front of an apartment building in the 4200 block of Kaywood Drive. Police said Knight and possibly others shot the Howard student in the head and back, although they are still exploring exactly why.

Julie Parker, a county police spokeswoman, said detectives were tipped to Knight’s involvement after they found his handprint on a stolen vehicle near the crime scene. She said they searched Knight’s home Thursday, and recovered what they believe is the assault rifle used in the attack.

Parker said Knight initially was held in the District on an outstanding auto theft warrant, and he is awaiting extradition to Maryland.

The case shocked Guyton’s friends, family and the Howard University community. The former Marine was interested in drums and keyboards.He was talking about proposing to his girlfriend, and he aspired to eventually compose and produce his own songs.

Parker said it did not appear Guyton knew Knight and said Guyton “may have struggled with his attacker.”

Mount Rainier Police Chief Michael Scott said previously that the attack appeared to be a robbery, if only because Guyton did not have his wallet when officers found him.

Online court records show Knight has been charged several times previously with armed robbery and carjacking. He was convicted of robbery in Montgomery County in June 2010 and unauthorized use of a motor vehicle in Prince George’s in April 2010.