Authorities in South Carolina have identified the man suspected of shooting and killing five people as former NFL player Phillip Adams.
Dr Robert Lesslie, 70; his wife, Barbara Lesslie, 69; grandchildren Adah Lesslie, 9; and Noah Lesslie, 5; and worker James Lewis, 38, were killed.
The family were found in their home in Rock Hill, South Carolina, 30 miles (48km) from Charlotte, North Carolina.
The attack came as President Joe Biden announced new gun control measures.
Officials said the murders were committed on Wednesday evening by Mr Adams, 32, who then killed himself after a standoff with police.
What do we know about the shooting?
Police said that Mr Adams’ parents live near the doctor’s home, and that he shot himself in a bedroom there after police attempts to get him to leave the house voluntarily failed.
The motive for the attack remains unclear.
“There’s nothing right now that makes sense to any of us,” York County Sheriff Kevin Tolson told reporters on Thursday.
Earlier on Thursday, a spokesman for the Sheriff’s Office, Trent Faris, said that “Dr Lesslie was my doctor growing up”.
“Dr Lesslie has been one of those people that everybody knows,” he said, describing the doctor as “a staple in Rock Hill for years”.
A person who spoke to the Associated Press on condition of anonymity said that Dr Lesslie had treated Mr Adams.
Mr Lewis was a technician with Gaston Sheet Metal Services working at the home, according to a Facebook post by the company. Another worker at the home, Robert Shook, was also shot and taken to hospital where he has undergone multiple surgeries.
“Both men involved in this incident are long-standing, beloved members of our family at GSM,” the company wrote on Facebook.
Dr Lesslie had been married to his wife for over 40 years, according to an online biography. He was a well-known doctor and author of books about medicine.
He also founded the Riverview Medical Center and Riverview House Calls/Riverview Hospice and Palliative Care.
Who is the suspect?
Mr Adams played in 78 NFL games over five seasons for six teams, including the San Francisco 49ers and New York Jets.
In the 2010 season, he suffered a severe ankle injury that left him with screws in his leg, according to CBS News. In 2012, he suffered two concussions over three games while playing for the Oakland Raiders.
A man who claimed to be Mr Adams’ father told WNCN-TV that his son was the attacker. “I think the football messed him up,” Alonzo Adams told the station.
“He didn’t talk much and he didn’t bother nobody,” he added.
On Thursday, an NFL spokesperson expressed condolences in a statement, saying: “Our hearts go out to the families and friends of the victims of this devastating tragedy.”
What did Mr Biden say?
Mr Biden was already scheduled to announce new gun restrictions on Thursday. He paid tribute to the victims during his address at the White House Rose Garden.
“As I was coming to the Oval Office I got the word that in South Carolina a physician, with his wife, two grandchildren and a person working at his house were gunned down. All five.”
“So many people sitting here today know that well,” Mr Biden told the audience, who included victims of gun crime. “They know what it’s like when the seconds change your life forever.”