Chelsea, MA Police Sergeant Arthur CashinPhoto: Chelsea PoliceSergeant Arthur Cashin was shot and killed while making a traffic stop. After stopping a vehicle for going the wrong way on a one-way street in Bellingham Square, Chelsea, Sergeant Cashin approached the driver's side of the vehicle as his partner, Officer William Copello, approached the passenger side. The driver got out of the vehicle and immediately punched Sergeant Cashin, who landed face first on the sidewalk. The driver then un-holstered Sergeant Cashin's service weapon and shot the officer twice in the back as he lay on the ground. Officer Copello then drew his service weapon, shooting and killing the driver. Sergeant Cashin was pronounced dead shortly after midnight on July 20th at Massachusetts General Hospital in Boston. Sergeant Cashin had been with the agency for nine years. He was survived by his wife and two young daughters. His nephew, Captain Rick Cashin, was killed in an on-duty automobile accident while serving with the Massachusetts State Police on January 28, 2009. Click this text to visit the Officer Down Memorial Page to write a tribute to Sergeant Cashin.