Middlesex District Attorney Marian Ryan has released the findings of an independent investigation into a fatal crash involving a state police sergeant in Woburn in 2023. The investigation, conducted by retired Superior Court Judge Thomas Drechsler, interviewed 34 witnesses, including 30 current and four former employees. The findings were released after a grand jury indicted State Police Sgt. Scott Quigley on a charge of felony motor vehicle homicide for allegedly being drunk when he crashed his unmarked cruiser head-on into a wheelchair-accessible van, injuring a man with developmental challenges who died a month later. The independent investigation also found another state police officer may have known Quegley was drunk at the time of the crash but did not disclose it properly.