Former NFL star Phillip Adams killed himself after shooting dead five people including a prominent doctor, his wife, and their two grandchildren, police say.
Police have not yet established a motive for the mass shooting in South Carolina on Wednesday.
“There’s nothing right now that makes sense to any of us,” York County Sheriff Kevil Tolson told a news briefing.
Dr Robert Lesslie, 70, and his wife, Barbara, 69, were pronounced dead at the scene along with their grandchildren, Adah Lesslie, nine, and Noah Lesslie, five, the York County coroner’s office said.
James Lewis, 38, from Gaston, was working at the property and was found shot dead outside, while an unidentified sixth person was taken to hospital with “serious gunshot wounds”.
After police discovered the five victims, they said evidence left at the scene led them to the home of Adams’ parents.
There, they led his parents to safety before trying to talk the former San Francisco 49ers and New England Patriots player outside.
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Eventually, Sheriff Tolson said, they found him dead of a single gunshot wound to the head in a bedroom.
According to the Associated Press news agency, Adams had been treated by Dr Lesslie, who lived near his parents’ home in the town of Rock Hill.
Adams’ father told a TV station in Charlotte, South Carolina, he blamed football for problems his son had, and which might have led him to commit Wednesday’s violence.
He told WCNC-TV: “I can say he’s a good kid – he was a good kid, and I think the football messed him up. He didn’t talk much and he didn’t bother nobody.”
Adams, 33, played in 78 NFL games over five seasons for six teams.
He joined the 49ers in 2010 and though he rarely started, he went on to play for New England, Seattle, Oakland and the New York Jets before finishing his career with the Atlanta Falcons in 2015.
As a rookie late in the 2010 season, Adams suffered a severe ankle injury that required surgery that included several screws being inserted into his leg.
He never played for the 49ers again, getting released just before the 2011 season began.
Later, with the then LA Raiders, he had two concussions over three games in 2012. Whether he suffered long-lasting concussion-related injuries is not known.
An NFL spokesman said: “Our hearts go out to the families and friends of the victims of this devastating tragedy.”
Anyone feeling emotionally distressed or suicidal can call Samaritans for help on 116 123 or email firstname.lastname@example.org in the UK. In the US, call the Samaritans branch in your area or 1 (800) 273-TALK