A Windsor Locks police officer has been charged with manslaughter in connection with an accident that killed a 15-year-old boy last month.

Michael Koistinen, 24, was arrested Thursday evening.

Koistinen was driving a car that hit and killed Henry Dang as the teen rode his bicycle at the intersection of Spring Street and West Street on Oct. 30. Koistinen was off-duty at the time of the accident.

Friends and classmates of Dang were relieved to hear there was an arrest.

"It was a matter of time before something came out, before someone got charged with something, and it's just good to know that it's finally out there," said Chelsea Santos.Koistinen admitted to tailgating at a UConn football game earlier in the night and video showed Koistinen had been drinking at a Suffield bar before the crash, but his attorney said that was not a factor in the crash.

"He was not drunk at the time of the accident," Elliot Spector told NBC Connecticut.

Henry Dang's brother told NBC Connecticut last week that State Police investigators had told him Koistinen's father, a sergeant with the Windsor Locks police department, went to the scene of the crash. Furthermore, police allowed Koistinen to go to the hospital without an escort.

Koistinen faces charges of First-Degree Manslaughter, Second-Degree Manslaughter, Misconduct with a Motor Vehicle, Negligent Homicide with a Motor Vehicle and Attempt to Commit Tampering with Physical Evidence.

"I don't think anything's going to change until we know the truth, until we know exactly what happened," said Jessica Kuzmickas, a friend of Henry Dang, who wants to know details of the crash.

Koistinen was released on $50,000 bond. Koistinen will be in court to face the charges on Nov. 23.