A Brockton man shot another, an officer, and then himself, police say. Here’s what we know.

Authorities in Brockton continued to search for answers on Friday after a 32-year-old man allegedly shot and killed a 28-year-old man and then turned the gun on himself following an hours-long standoff with police the night before.

The Plymouth County District Attorney’s Office identified the alleged gunman as Kevin Serpa and the victim as Christopher Gomes, both of Brockton.

A Brockton police officer also suffered nonlife-threatening injuries when he was shot by Serpa while responding to the scene, officials said.

The officer, who was not identified, had been released from Boston Medical Center by late Friday morning, prosecutors said.

“You look around, this is a very dense neighborhood. It’s a very, very dense neighborhood,” Brockton Mayor Robert Sullivan told reporters near the shooting site on Thursday night. “My thoughts as mayor and as a lifelong Brocktonian is to the brave individual that took four shots tonight. We’re very thankful. We hope that he has a speedy recovery.”

A motive for the string of violence was not yet clear to investigators on Thursday, as they began an investigation to understand why shots rang out on Taber Avenue, setting forth a flurry of 911 calls and a horde of local, state, and federal authorities to a home on the dead-end street.

“We’re in the process of executing search warrants and making sure that we do all of our due diligence to make sure we find everything that we need to find,” District Attorney Timothy Cruz said during the Thursday night press conference.

“We’re going to make sure we’re very thorough, and we find out exactly what happened here,” he added later.

Here’s what we know so far:

What authorities say happened

Around 5:45 p.m. Thursday, Brockton police received several emergency calls reporting a man with a gun and gunshots fired near 62 Taber Ave., according to Cruz’s office.

Responding officers found a man, later identified as Gomes, with gunshot wounds inside a silver SUV near the residence, where gunfire was coming from a second-floor window, prosecutors said.

Gomes was determined to be dead, a spokesperson for Cruz’s office said Friday.

An officer was also struck by the gunfire. According to WCVB, the officer appeared to have been shot in the hand and leg.

Brockton police called on Massachusetts State Police, including the agency’s crisis negotiation team, according to authorities.

“A perimeter was set up in the densely populated neighborhood,” Cruz’s office said in a statement released Friday. “State Police and Brockton Police were in constant contact and negotiated with the barricaded Serpa throughout the night.”

Around 9:30 p.m., Serpa left the home and shot himself outside, authorities said. He was brought to Good Samaritan Hospital, where he was pronounced dead at 10:02 p.m.

The negotiators “did their very, very best to make sure they could make this a peaceful situation, and unfortunately it didn’t end that way,” Cruz said.

At the scene was one of Serpa’s childhood friends who tried to assist in helping Serpa leave the home without incident, WCVB reports.

“I was with his father for a little bit, and they were negotiating back and forth, and from my understanding, the negotiators actually said he was outside,” the friend, who did not want to be identified, told the news station. “I kept praying left and right, just come out, surrender yourself. You know, you’re going to go to jail, but you’ll still be alive.”

Cruz, at Thursday’s press conference, dismissed rumors that a child was present in the home and said police brought in equipment to determine whether there were explosives on the premises, as expressed in other allegations.

State and Brockton police will review video surveillance footage from the area and interview witnesses, Cruz’s office said. The incident did not appear to be “an act of random violence,” officials said.

“Police officers, men and women that every day show up at scenes, they do tremendous jobs,” Cruz said. “And watching this go down tonight, I think it was some great jobs by police officers trying to do the best they could in an incredibly difficult situation.”

‘This is definitely a calling to him’: The injured officer recently joined the force

Brockton Police Chief Emanuel Gomes praised the actions of the injured officer while speaking to reporters on Friday.

“His actions saved his own life, possibly the lives of others. And I’m very happy that he’s home and he’s healing,” the chief said. “He’s in some pain, but he’s been released, and I couldn’t be happier to report that.”

Emanuel Gomes also applauded doctors at Boston Medical Center, who he said took a “cautious approach” to treating the officer’s injuries, since he still has a bullet lodged in him.

“He’ll need a lot of different resources from emotional to physical therapy down the line, but … he is out, and we are so thankful and our prayers and thoughts are with him as he continues to recover,” Sullivan said Friday.

According to the police chief, the officer had recently graduated the Boston Police Academy, whose training “played a role last night,” he said.

“This is definitely a calling to him,” Emanuel Gomes said of the officer. “And he showed it.”

Police anticipate an ‘a long and arduous investigation’

Responding to a question, Emanuel Gomes told reporters on Friday that investigators did not know whether Christopher Gomes and Serpa knew one another.

“It’s still in the preliminary stages,” he said. “As you can imagine from everything last night, it’s going to be a long and arduous investigation to complete that and we don’t even have those preliminary things yet.”