In it, they allege that Harran clashed with the elder Jerri and forced him to quit after allegedly orchestrating the March 2012 arrest of his son on theft and insurance-fraud charges.
David Jerri Jr. was acquitted at trial of any wrongdoing.
In court documents, DiGirolamo, Harran, Deputy Public Safety Director Patrick Ponticelli, and Detective John Monaghan have denied allegations that they pursued the charges for political reasons.
Asked Thursday if he invoked his Fifth Amendment right during the case, Harran declined to comment and deferred questions to his attorney, Richard Morris, who did not reply to a request for comment.
DiGirolamo, a Republican who has been mayor for nearly two decades and is the uncle of State Rep. Gene DiGirolamo (R., Bucks), also did not return a message left for comment. His attorneys, John Morgenstern and Rufus A. Jennings, did not return calls or e-mails. Nor did Ponticelli, Monaghan, or their lawyers.
The attorney for the Jerris, Brian K. Wiley, declined to discuss the case.
According to their lawsuit, the dispute started as a not-so-uncommon political feud between Harran - a 27-year veteran of the force who oversees Bensalem's police and fire departments - and the elder Jerri, who became chief of the volunteer fire company in 2011.
The suit alleges that Harran had interfered with the fire company's operations as far back as 2010, and said that when Jerri Sr. took over as chief, he became a vocal critic of Harran and other township administrators.
A heated exchange took place in 2012 over a $1 million Delaware River rescue boat the company bought with federal grant money. At the time, Harran called the fire company "nuts" and police implored the FBI to investigate the purchase. Jerri in turn described Harran as a bully.
The Jerri lawsuit alleges that Harran used a variety of tactics to intimidate the fire chief and force his ouster.
In the fall of 2011, Jerri's son began collecting worker's compensation for a hand injury he said he suffered while fighting a fire with the fire company.
In December 2011, according to court records, his benefits were cut off. The payments stopped at Harran's direction, a representative for the insurer later testified.
Around the same time, Monaghan - also at Harran's direction - began investigating if his injury was truly job-related, testimony later showed.
The detective interviewed two of the younger Jerri's coworkers at an auto garage, court documents say, and both recalled his missing a day of work just before the fire because of a hand injury he said he suffered during a hockey game. They also recalled his later saying that he aggravated the injury during the fire, the records say.
In March 2012, about three months after Jerri's worker's compensation had been terminated, police charged him with insurance fraud and theft by deception, claiming his injury occurred during the game and citing the interviews with the coworkers.
That summer, Harran shut down the fire company for the second time in a little more than a year. He said he would reopen it if only Jerri Sr. resigned. So the fire chief stepped down.
In November 2012, the younger Jerri went on trial in Doylestown before County Court Judge Albert J. Cepparulo. During the trial, Monaghan testified that he never interviewed anyone on the hockey team or documented any attempts to do so.
According to the transcript, when the judge asked Monaghan why he didn't keep a record of attempts to find additional witnesses, he replied: "I couldn't tell you why."
Cepparulo ultimately acquitted Jerri on all counts.
Deputy District Attorney Ryan Hyde, who prosecuted the case, said this week that he believed the evidence "was sufficient" for a conviction.
The Jerris filed their lawsuit in federal court in Philadelphia last March, seeking damages and their jobs back.
According to a brief filed by Wiley, the Jerris' attorney, in January, Harran, Ponticelli, Monaghan, and DiGirolamo pleaded the Fifth Amendment when they were asked "whether they lied, omitted and/or withheld information from prosecutors" relating to the charges against Jerri Jr. It was unclear when the questions were asked or in what form.
The animosity between the two sides has coursed through the proceedings. In a December hearing, Baylson told the lawyers: "There are a lot of feelings here, and I understand that."