They met on Tinder. Now she’s recovering from stab wounds, and he’s dead after getting tased by police.

Police in Cohasset last week used tasers to subdue a man who was allegedly attacking a woman in his home with a knife. The 25-year-old man, identified by authorities as Erich Stelzer, became unresponsive at the scene and later died, while the woman — Maegan Tapley, 24 — was hospitalized with “extensive” injuries.The investigation into the incident and the 25-year-old’s death remains ongoing. The Norfolk District Attorney’s office said on Monday that an autopsy for Stelzer was conducted by the Office of the Chief Medical Examiner, but the cause and manner of his death are “pending” the results of toxicology testing. Here’s what we know about the violent event that has shocked the Cohasset community.

What authorities say happened

The incident began on Thursday night when Cohasset police responded to a 911 call just before 10 p.m. for a report of a “disturbance” at Stelzer’s residence on Church Street. When officers entered the home, they saw Stelzer assaulting a woman with a knife and “other weapons,” according to the DA’s office.“In an effort to rescue the victim and disarm Stelzer, Cohasset Police Officers used tasers to subdue Stelzer,” Peggie Krippendorf, a spokeswoman for the Norfolk District Attorney’s office, said in a statement Friday afternoon. “The female victim was able to escape from Stelzer and was taken to a local area hospital for treatment.” The woman, identified by her family to NBC10 Boston as the 24-year-old Tapley, suffered extensive stabbing and slashing wounds, according to authorities. The DA’s office said EMTs “immediately” began to provide medical treatment to Stelzer, but, while he was being transported to a local hospital, he became unresponsive and later died. An official told The Boston Globe that Stelzer and Tapley met on the dating app Tinder.Cohasset Police Chief William Quigley praised the actions of his officers following the incident in a statement released to Boston 25 News. “I’m extremely proud of the job my officers did,” he said. “They acted heroically and absolutely saved a life. While it’s sad there’s a loss of life, they did great work.”

What we know about Erich Stelzer

Erich Stelzer.

The father of the 25-year-old Cohasset man, Harold Stelzer, told NBC10 Boston following his son’s death that he was looking for justice.

“I have a very high-priced lawyer — very high-priced. People will know him, and he’s going to put this together,” he said. “I’m not looking for money; I’m looking for justice.”

Harold Stelzer told the station that a stun gun was used four times on his son, which he described as “excessive.”

“I know that one hit is substantial,” he said. “Two will knock you down. There were four cops there. Can’t they handcuff him?”

Stelzer was about 6-foot-8 and 300 pounds, his father told the station. The 25-year-old was a bodybuilder, according to MassLive, documenting his fitness routines on Instagram and YouTube.

Harold Stelzer said Friday he was in total shock.

“I do not even know what is going on,” he told 7News Boston. “I do not know where this behavior came from. He was just a happy go lucky guy. I am sorry for what happened to the girl. I mean, what can I say, but until I get the report I cannot make judgment. No one wants that to happen to their daughter.”

On Saturday, Stelzer’s family released a statement through an attorney, expressing sympathy for Tapley and her family and revealing they’d sought help for the 25-year-old in the days before his alleged attack on his Tinder date.

“The family of Erich Stelzer wishes to express its deepest sympathy for the victim and her family,” Philip Cormier, a lawyer, said in the statement, according to MassLive. “They are without words to adequately communicate their grief and sorrow at the events that transpired, the physical and mental pain caused to the victim, and the loss of life of a young man who was someone’s little brother and someone’s son.”

Stelzer had been receiving care from mental health professionals over the past month, his family said, but, during a gathering on Christmas, they had noticed more of a decline. He was experiencing delusions and extreme paranoia and behaving erratically, the family’s lawyer said.

“[I]t became clear that his needs were not being met,” the statement read.

Believing Stelzer was having a “psychotic break,” his family called Cohasset police and EMTs to perform an assessment on Dec. 25.

“The assessment by the EMTs was that he did not need assistance due to the fact that he was lucid enough to know his own name and the date,” Cormier said in the statement, reported by MassLive. “The family was surprised and unsure how to proceed.”

The family hired a professional intervention team the next day to get Stelzer into an inpatient treatment facility, but the events of Thursday night took place “before the intervention could be implemented.”

What we know about Maegan Tapley

Maegan Tapley.

Susan Tapley told NBC10 Boston that her daughter has a long recovery ahead of her.

“She’s going to mend, she’s going to be alright. It’s going to take time to recover,” she told the station. “She’ll need plastic surgery and an eye specialist.”

Tapley’s sister told Boston 25 News that the 24-year-old had been working as a veterinary assistant at an animal center in Saugus for three years and she is the youngest of three.

“My sister has been through a horrific attack that would have killed her had the police not arrived,” Tapley’s sister told the station. “It’s going to be a long recovery due to extensive wounds, but she’s an amazing, strong, young woman and will get through this. Her family and friends are here for her and will be by her side throughout this recovery.”

Friends of Tapley’s family have started a GoFundMe to help pay for her medical expenses.

“On Thursday December 27, Maegan Tapley fell victim to a domestic violence dispute that could have ended her life, if not for the heroic efforts of the Cohasset Police Department,” the organizer wrote. “Maegan’s injures are extensive and will require many surgeries. Her recovery will take a very long time.”

More than $3,900 had been donated in the day since the fundraiser was started.

Susan Tapley told NBC10 Boston that her daughter met Stelzer on Tinder.

“I feel for [Steltzer’s] mother,” she told the station. “She just lost her son. My daughter almost died because of his lunacy.”