FALMOUTH, Maine — A part-time firefighter has been arrested for arson after allegedly setting two fires in September, according to police.

Griffin Kline, 20, of Woodlands Drive, was arrested Wednesday night following a two-month investigation, according to a press release from Lt. John Kilbride.

Kline was also indicted earlier this month for alleged sex acts with a minor.

On Sept. 14, firefighters responded to a suspicious dumpster fire at 161 Woodlands Drive. Several hours later, a second fire destroyed a “small wooden structure on the golf course containing bathrooms for the Woodlands Country Club,” the release states. The structure was valued at $30,000.

At the time of the fires, Kline served as a part-time, on-call firefighter for the Falmouth Fire/EMS Department, but he was placed on unpaid leave “immediately following information that identified him,” according to a separate news release from Town Manager Nathan Poore.

“Since that time, he has not responded to Fire/EMS calls and has not been permitted on town property,” the release said. “He has had no association with the Falmouth Fire/EMS Department.”

Fire Chief Howard Rice congratulated police and the state fire marshall’s office for their joint investigation, adding that it was troubling that Kline was involved.

“Fighting fires and ensuring the safety of all people in this community is what we dedicate our lives to doing, so it is particularly disturbing to discover that the perpetrator was one of our own,” Rice said in the release.

Kline is scheduled to be arraigned on Jan. 16, 2014.

Earlier this month, a Cumberland County grand jury handed up two indictments against Kline for charges including alleged sexual acts with a minor.

Kline was indicted Nov. 8 for gross sexual assault of a minor, sexual abuse of a minor, violating a protection order, and violating conditions of release, according to Tamara Getchell, communications coordinator for the Cumberland County district attorney’s office.

Getchell would not discuss specifics of the cases, but said the indictments stemmed from three separate incidents that took place between September 2012 and October 2013 in North Yarmouth, New Gloucester and Gray.

Indictments are findings that enough evidence exists to prosecute, not findings of guilt.

The first indictment dealt exclusively with two incidents allegedly involving the same minor. Kline is accused of gross sexual assault, a class A felony, with a minor of less than 14 years of age, sometime between Sept. 1, 2012, and July 25, 2013, in North Yarmouth. He is also accused of sexual abuse, a class D misdemeanor, with the same minor on or around July 25 – the victim’s 14th birthday – in New Gloucester.

The reduced severity of the second charge is a result of the victim’s age at the time, Getchell said.

The second grand jury indictment stems from an incident on Oct. 17 in Gray, when Kline allegedly made contact with the victim, a violation of a protection order. He was also indicted on two counts of violating conditions of release in that incident.

Kline was also arrested on Oct. 30 in Falmouth on a charge of domestic violence assault.