On August 20, 2006, around 2:06am, officers in District 11 responded to a radio call on a report of a pedestrian struck at 445 Quincy Street in Dorchester. On arrival the officers observed Boston Firefighters and EMS treating a victim lying in the street in front of 439 Quincy Street suffering from severe head trauma. The victim has been identified as William Edward Welch, 26, of Dorchester. Welch was transported to the Boston Medical Center where he was pronounced. According to witnesses, a grey/silver light colored Ford Taurus with a for-sale sign in the back window was traveling at a high rate of speed down Quincy Street when it hit the victim. The vehicle then continued toward Clarkson Street, stopped and returned to see what it struck. The suspect then fled down Quincy Street without making him/herself known.Boston Police are urging the suspect to make him/herself known. Anyone with any information about this incident is urged to contact the Boston Police Homicide Unit at 617-343-4470 or to remain anonymous call the Crime Stoppers Tip Line at 1-800-494-TIPS.