OAKLAND — Jason Thomas was smoking a cigarette on his back deck on Belgrade Road shortly after 8 p.m. Wednesday when he heard a commotion next door. He then heard two gunshots, a man yelling and a woman pleading, “Please no, please help me.”

Thomas went into his house, locked the door and barricaded it with chairs. Then, like many of his neighbors, he called 911.

After Thomas secured his house and called police, he dialed the number of Michael Muzerolle, who lived on the first floor of the neighboring multifamily house with his girlfriend, Amanda Bragg. When Bragg picked up, he asked her if she was OK.

“She said, ‘No, I can’t move. Please help,’” Thomas said. He told her that the police were on their way, but Bragg kept asking for help.

Then the line went dead.

Meanwhile, Bragg’s sister, Amy Derosby, also had called 911. With her dying breaths, she gave police “very valuable information that helped first responders when they got there,” although authorities won’t say what she said.

Derosby, along with Bragg and Muzerolle, were shot and killed by Herman Derico in the two-unit house they shared at 41 Belgrade Road, police said. Derico then shot himself outside in the driveway.

Bragg’s and Muzerolle’s 3-year-old daughter, Arrianna, was found unharmed in the first-floor apartment by the first police on the scene.

A day after the deadly shootings stunned the Oakland community, authorities said they still don’t know why Derico gunned down the three adults in the first-floor apartment rented by Bragg, 30, and Muzerolle, 29. Derico, 42, and Derosby, 28, were dating and lived upstairs. Landlord Paul Seluke lives in a third apartment in a barnlike addition out back.

“What state police and Oakland police are trying to determine is what sparked the violence here last night, and at this hour, we do not have answers,” Department of Public Safety spokesman Steve McCausland said during a news conference Thursday afternoon in front of the scene. “We will work on getting that answer, but there’s no guarantees we’re going to come up with an answer. At this point, that answer is elusive.”

Wednesday’s shootings, the first homicides in Oakland in more than a decade, shook the small, tight-knit community and hit especially close to home for Police Chief Michael Tracy. Muzerolle was his nephew, the only child of his youngest sister. Tracy was the one who called his sister in Florida to give her the tragic news.

“She took it really hard,” as any parent would, Tracy said in his office Thursday morning.

LITTLE KNOWN ABOUT THE SHOOTER

There were no warning signs that the shooting was going to happen, said Tracy, who didn’t know Derico or Derosby. He ran into Muzerolle around town, but couldn’t remember the last time he saw his nephew.

Scant information was available on Derico, who McCausland said “is not from Maine,” although police didn’t know how long he had lived here. Police contacted his relatives Wednesday night. His mother lives in California and his grandmother lives in Alabama.

Ron Pressey, who lives on Old Belgrade Road around the corner from where the shooting occurred, said he often saw Derico and Derosby and their dog sitting outside the brown house with white trim that has a neatly kept yard with flower baskets.

“From what I was told, he came from New York to Portland to here,” Pressey said. “Something in his past brought it up to this point.

“Things happen, but this is very, very sad. Now you have a child that will be scarred for life.”

McCausland said Arrianna would be cared for by her grandmother, the mother of Bragg and Derosby.

NEIGHBOR HEARD SHOTS, SAW GUNMAN

Thomas, the next-door neighbor who called police Wednesday night, didn’t know Derico well, but the two connected because they were fans of the Oakland Raiders NFL team. He heard occasional arguments next door, but nothing serious.

“Obviously, as a neighbor you hear things,” he said.

McCausland confirmed Thursday that Derico didn’t have any criminal history in Maine, but investigators had not completed a nationwide criminal check as of Thursday. Police were still tracing where Derico obtained the 9 mm gun used in the shooting, McCausland said.

According to court records, Derico was fined $350 in Kennebec County court in September for possessing up to 1¼ ounces of marijuana.

“There has been no interaction between him and Oakland police. About the only contact is that they would see him sitting on the steps as they drove by,” McCausland said.

Chris Perry, who owns a home next door to where the shootings happened, said he was pulling into his driveway when he heard two gunshots.

“As soon as I put my car in park, I heard ‘bang, bang,’ ” Perry said. “I thought I hit my garage door.”

Perry got out of his car, and as he was unlocking his door he saw Derico walking around outside. He didn’t try to talk to him or make eye contact, Perry said.

“I thought if they are just having an argument, I didn’t want to call the cops,” he said.

A few minutes after he went into his house, police showed up and told him to seek shelter in a back room. He could see officers with drawn guns and flashlights working their way toward the house next door.

About 20 minutes later, another officer came by to tell him to leave, Perry said. On his way out of Oakland, he could see emergency vehicles streaming past him on the road, headed toward the shooting scene.

The Oakland Police Department responded to the initial reports and called for assistance from the Maine State Police. A state police tactical team was sent to the scene, Lt. Troy Gardner said at a 3 a.m. news conference Thursday.

Police from at least six agencies converged on the scene after the initial report Wednesday night, including the Fairfield, Oakland, Waterville and Winslow police departments and the Kennebec County Sheriff’s Office.

Belgrade Road initially was blocked at the intersection of Church Street and Libby Hill Road, which is Route 23.

When the tactical team first entered the house to get Arrianna, they found two bodies. The third body was found when the team re-entered the apartment later Wednesday night, McCausland said. It’s unclear whether the child witnessed the shootings, he said.

“She was in the apartment at the time. What she saw, what she heard, I don’t have any particulars on that,” he said.

In a statement Thursday morning, the Family Violence Project noted that many details of the incident were not known yet, but that the case makes clear “violence in the home … affects everyone, including the victim(s), family and all members of the community.”

There have been 17 homicides in Maine so far in 2015, including the shootings Wednesday, McCausland said. He did not know how many of the homicides were related to domestic violence. The Family Violence Project encouraged people to use its confidential support line at (877) 890-7788.

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