SOUTH WINDSOR, Conn. (AP) — Police say a Connecticut police officer has died from injuries he sustained while trying to break up a bar fight in South Carolina. South Windsor Police say 41-year-old Matthew Mainieri was a 20-year veteran of the department. The Hartford Courant reports Mainieri was attempting to break up the fight when he sustained a fatal blow to the head. Mainieri was off duty at the time and died Sunday from his injuries. County sheriffs in South Carolina charged 21-year-old Kelton Jess Todd in the assault. He was taken to a local jail. It’s unclear whether he’s represented by an attorney who could comment. Police are still investigating and may add further charges. Over his two-decade career, Mainieri received his department’s Medal of Valor, the Chief’s Award and multiple certificates of commendation. Close The biggest headlines, delivered to your inbox Get news as it happens. Sign up for Boston.com’s email news alerts. Thanks for signing up!