A Centralia police officer is free on bail after being charged Monday in Marion County court with two counts misdemeanor domestic battery.  Mason Jackson has been suspended with pay since the alleged incident in March at the Huck’s station in Centralia.  According to Centralia Police Chief Doug Krutsinger, a warrant was issued Monday for Jackson’s arrest, following an investigation by the Illinois State Police that was launched soon after the alleged domestic battery incident in March.  Court records indicate the argument reportedly began while Jackson and his girlfriend were out for the evening, and when they returned home, Jackson reportedly took his sidearm from its holster, put the gun to his girlfriend’s head and ultimately put the barrel of the gun in her mouth.  When the girlfriend attempted to leave the home, Jackson reportedly physically stopped her from leaving the home.  But when the officer went to bed, the woman reportedly took the keys to her car and fled, with Jackson in pursuit a short time later in another vehicle.  The two ultimately ended up at the Huck’s station on East Calumet, with Jackson allegedly blocking in his girlfriend’s car.  Police were called when a passerby attempted to intervene and alerted a customer entering the store to call.  Jackson was suspended the first day he returned to work following the alleged incident, and Krutsinger notified ISP to have an outside agency investigate the allegations against the officer.  Jackson, says Krutsinger, was notified Monday of the warrant, and turned himself in before posting $750 bond.