A 20-year-old Montgomery County man was booked early Saturday on first-degree murder charges in the death of Michael Kirby Alvarado, a former Gaithersburg High School football star who was found shot Thursday at an apartment complex near his home.

About 8 p.m. Friday, detectives closed in on the suspect, Jefferson Daniel Delgado, in the Silver Spring area. They stopped a vehicle he was in, and he tried to flee, police said. Delgado later was taken to the Montgomery County Detention Center, where he was being held Saturday without bond, according to court records.

Police said they continue to investigate other possible suspects in the case. As for what led to the shooting, officials wouldn’t say, but they indicated that it was not a completely random event.

“Police believe that Delgado and Alvarado knew each other,” police officials said in a news release Saturday morning, “although the exact nature of their relationship is still under investigation.”

About 2:30 p.m. Thursday, police were called to the Streamside Apartments in Gaithersburg, where they found Alvarado shot at least once outside a three-story apartment building. He was pronounced dead at the scene. Since the killing, police have said they were looking for two suspects — one wearing all black clothing, the other wearing a black and white striped shirt.

Michael Alvarado, seen here in the 2008 William and Mary Football Media Guide, was shot and killed in Gaithersburg, Md. Alvarado was 25 years old. (College of William and Mary)

The death of Alvarado shocked many in the Gaithersburg area. The gifted athlete also was a good enough student to receive a football scholarship to the College of William and Mary, where he pursued a business major. But Alvarado withdrew from the school in spring 2010 without receiving a degree.