WARREN, Maine — The public works director for the town has sued the former chairman of the board of selectmen, claiming the official assaulted him more than a year ago.

The lawsuit filed July 1 by Douglas Gammon against Michael York seeks unspecified damages for assault and deprivation of constitutional rights.

In November, District Attorney Geoffrey Rushlau announced no criminal charges would be filed in the matter, saying he did not believe the state could prove beyond a reasonable doubt that either man was not acting in self-defense. Rushlau pointed out that the only two people who witnessed the Nov. 5, 2014, altercation were York and Gammon.

The standard of proof in a civil lawsuit is less than for a criminal conviction.

Rushlau said each man claimed the other was the aggressor. The two also disagreed on exactly where the altercation occurred, the prosecutor said, with Gammon maintaining it occurred on his property.

The issue of where the incident occurred was crucial to whether York could be prosecuted for criminal trespass or to determine if Gammon was justified in using force to end a trespass, Rushlau had said.

Gammon filed a notice of claim with the town in December 2014 indicating he intended to sue the community for more than $150,000 in damages.

York ran for re-election shortly afterward, in March 2015, and was defeated in a write-in campaign by former state representative Wes Richardson.

In his lawsuit filed July 1, Gammon states that York came on his property to check on the status of a town snow plow. Gammon said York began yelling at him and then grabbed and bent back Gammon’s thumb, tearing a ligament and damaging a tendon.

Last year, York’s attorney Christopher MacLean, said Gammon punched York in the face without provocation. An email message sent Monday morning to MacLean was not immediately returned.

Gammon is represented by attorneys Walter McKee and Matthew Morgan of Augusta.

The town is not named in the lawsuit. Warren Town Manager William Lawrence said Monday there has been no action against the town on the matter since the notice of claim was filed.