Maurice Bellamy walked up to 15-year-old Davonte Washington on a D.C. Metro platform on Saturday and shot him dead in front of Washington’s mom and two younger sisters, officials said Tuesday as the suspect was charged with second degree murder while armed.

Bellamy, 17, will be tried as an adult, FOX5 reported.

D.C. Police Chief Cathy Lanier said it was unclear whether Bellamy and Washington knew each other.

Washington’s murder has drawn nationwide attention in part due to the seemingly senseless nature of the act and also because his family said authorities were slow to respond, initially allowing the shooter to get away.

Washington, a ninth-grader and Air Force junior ROTC member, was on the Metro platform at 4 p.m. on Saturday with his family, headed to get a haircut, when a man now alleged to be Bellamy approached him and opened fire, NBC Washington reported. He later died at the hospital.

“They were on the platform. [His mother] said the guy walked up to them and asked him what was going on. He said, ‘Nothing.’ The guy said, ‘I’ll shoot you,’ and he shot him,” said Victor Leonard, Washington’s grandfather. “Just like that.”

A GoFundMe page to help with Washington’s funeral costs has raised $4,227 in one day.

Click for more from FOX5.