BELFAST — Angela and Joseph Mitchell Jr. had gotten used to the parties, the noise and the arguments at the house next door on Waldo Avenue.

So when they heard two men shouting late Wednesday, it wasn’t out of the ordinary.

But this time, the shouting ended with a loud pop, followed by a woman screaming. Followed by another pop.

Joseph Mitchell called 911. Police responded within minutes, guns drawn. The couple kept their four children inside. “I had a pretty good idea what happened,” Mitchell said.

When police arrived at 162 Waldo Ave., they found three people inside. Lynn Arsenault, 55, once named Lynn Day, had been shot to death. Her son, Mathew Day, 22, had been shot but was alive. Another man, John Riley, was in the house, unharmed.

The person who shot the two was nowhere to be found, but Riley and Day told police that the man was Todd Gilday of Belfast.

For several hours early Thursday, police searched the Belfast area for Gilday, 44, or his vehicle, a silver Nissan sedan with a vanity license plate that reads “FOREX.”

About 7 a.m., police got a tip that Gilday had checked into Penobscot Bay Medical Center in Rockport, south of Belfast, for unknown reasons. He was arrested at the hospital.

Late Thursday afternoon, Gilday made his initial appearance in Waldo County Superior Court on one count of murder and one count of elevated aggravated assault.

He spoke only briefly when asked by Justice Robert Murray if he understood the charges against him. He did not enter a plea.

Gilday will be held in the Two Bridges Regional Jail in Wiscasset pending a bail hearing, which will be held within the next five days unless Gilday or his attorney requests more time.

Police released few details about the circumstances of the shooting, but Maine State Police Lt. Christopher Coleman said Gilday knew at least one of the people in the home. “This was not a random act,” he said.

An arrest warrant filed Thursday before Gilday’s court appearance shed some light on the shooting but did not address any possible motive.

The court document, written by state police Detective Ryan Brockway, says three local police officers went to the home shortly before 11 p.m. Wednesday. They were met by Riley, who told them to hurry.

Riley told officers that he did not have a gun and that the gunman had fled.

When officers entered the home through a back deck, they saw a man lying across a woman on the floor of the kitchen. The man, identified later as Day, was bleeding from his stomach. The woman, identified as Arsenault, was “obviously deceased with what appeared to be a gunshot wound to her left shoulder and chest area,” the affidavit says.

Riley told police that a man had come to the house and been met by Day at the door. The two argued, and Day tried to close the door to keep the man out of the house. But the man pushed through the door, shattering the glass. He shot Arsenault, and then shot Day before leaving.

Riley and Day identified the man as Todd Gilday, but said they didn’t know why he came to the house or why he started shooting.

Gilday lives less than two miles from the scene of the shooting, in a large condominium complex called Spring Brook. Late Thursday morning, a Belfast police officer guarded the home and said detectives would likely search it later in the day.

Neighbors there said they knew little about Gilday.

He worked briefly as a tax examiner for Maine Revenue Services, but recently was terminated from that job, according to a spokesman for the agency.

“He was in his probationary period as a new hire and he was terminated within that time,” said David Heidrich.

Gilday has an online profile on Twitter, but is not a regular poster. Among the businesses he follows on Twitter are weapons companies such as Barrett Rifles, Elite Ammunition, Crimson Trace and Ingalls Gunsmith.

Angela and Joseph Mitchell said they don’t know Todd Gilday, but they did know Lynn Arsenault.

Angela Mitchell said she worked with Arsenault at Bank of America, one of Belfast’s biggest employers.

Arsenault worked at least part time at Bank of America and stayed with her son sometimes, according to police. The rest of the time, she lived in Garland with her husband.

The Mitchells said Arsenault bought the home next to theirs several years ago. The yellow, two-story raised ranch is slightly run-down.

“It was a party house, a drug house,” said Angela Mitchell.

The Mitchells said they called police often to report drug activity or rowdiness.

Belfast police refused to answer questions about any past dealings with the occupants of 162 Waldo Ave. and referred all questions to Maine State Police. Spokesman Stephen McCausland said he had no information about any previous police activity at the house.

Gilday has no criminal history in Maine.

Mathew Day was charged recently with aggravated assault and domestic violence assault, and was supposed to make a court appearance Thursday in Waldo County Superior Court.

He was rushed to Eastern Maine Medical Center in Bangor for emergency surgery, police said.

The police affidavit said Day suffered a “life-threatening gunshot wound,” but McCausland said late Thursday night that Day’s condition had “improved steadily throughout the day.”

McCausland said that, as far as he knew, Day was still in the Bangor hospital. But Andy Soucier, a spokesman for the hospital, said he could not confirm that Day was there.

Soucier said that could mean several things, including that Day had not authorized the hospital to release his condition.

Day’s attorney, Steven Peterson of Rockport, said he didn’t find out about the shooting until Thursday morning, when his client failed to show up in court.

Peterson said he knew Day’s mother.

“She’s the one who retained my services for her son,” he said. “She was a real nice lady. This is a terrible tragedy.”

Lynn Arsenault had no criminal history. In 2002, she filed a protection-from-abuse order against her husband, Robert Day, according to a Waldo County Superior Court clerk. The couple divorced that year.

Arsenault remarried recently, according to Angela Mitchell. Attempts to reach Arsenault’s husband and ex-husband were unsuccessful Thursday night.

Pamela Lufkin, who works at a cafe in the Bank of America call center in Belfast, said she saw Arsenault daily. “She was a strawberry blonde with a heart of gold” and a taste for Starbucks coffee, Lufkin said.

Arsenault was in the second week of a two-week vacation, Lufkin said, and was due to return to work Tuesday.

“The whole top floor of Bank of America was pretty shaken up today,” Lufkin said. “You couldn’t find a nicer person than Lynn.”

The Mitchells, who said they didn’t sleep much Wednesday night, said they don’t know what happened in the house beyond what they have been told by police. They said they are devastated by Arsenault’s death but not surprised by the violence.

“I’m sure this has something to do with drugs,” Angela Mitchell said.

– Staff Writer Edward D. Murphy contributed to this report.

Eric Russell can be contacted at 791-6344 or at:

erussell@pressherald.com