Two officers have left the Plymouth Police Department in the span of a month. The latest departure was Jonathan Yule, a patrolman who has been out on leave since December 2011 and has been not been paid since February, said Police Chief Michael E. Botieri. The chief said Yule resigned in November “to explore other opportunities.” Yule did not return a phone call seeking comment. Sergeant Shawn Coughlin went on leave around the same time as Yule and was terminated Oct. 17, Botieri said. According to an indictment from US Attorney Carmen M. Ortiz’s office, Coughlin allegedly assaulted a man who was handcuffed in a holding cell on Nov. 19, 2011, then tried to cover it up by falsifying and omitting information from police reports. Coughlin pleaded innocent to the charges and his lawyer, Thomas Drechsler, said Coughlin’s actions were “reasonable, necessary, and appropriate.” Coughlin’s next court date is Dec. 10 for an initial status conference before US Magistrate Judge Marianne B. Bowler.