A former National Football League player shot and killed five people — a prominent doctor, his wife, their two young grandchildren and a worker at the physician's South Carolina home — before killing himself in his own family's home nearby, authorities said. 

Phillip Adams, 33, went to the house of Dr Robert Lesslie on Wednesday, killing him, his wife, Barbara, 69, and grandchildren Adah Lesslie, 9, and Noah Lesslie, 5. 

Two air conditioning technicians were at the house working; one, 38-year-old James Lewis, was killed, and the other, identified as Robert Shook, was hospitalized in critical condition.

York County Sheriff Kevin Tolson said that Adams forced his way into the house after shooting the workers outside and fired as many as 20 shots at his victims.

After an eight-hour manhunt, police found Adams at his parents' house down the road. He died of a gunshot to the head inside the house as law enforcement officials tried to negotiate with him, authorities said. 

The shootings took place in Rock Hill, population 67,000, about 26 miles south of Charlotte, North Carolina.

Tolson said authorities don't yet know the motive for the shootings. He said detectives haven't confirmed reports from friends who said Adams had been a patient of Lesslie's. 

Adams' father, Alonzo Adams, said in a television interview that Lesslie used to be his doctor years ago. Adams told a Charlotte television station that his son had committed the killings, then had taken his own life. 

"I can say he's a good kid. He was a good kid," Adams said. "I think the football messed him up. I don't think he ever did anybody any harm. All I can say is we pray for the family. He used to be my doctor a long time ago. I know they were good folks down there. We're going to keep them in our prayers."

"We are truly in the midst of the unimaginable. The losses we are suffering cannot be uttered at this time," the families of the Lesslies said in a joint statement, read by Tolson.

Adams played in 78 NFL games as a cornerback over five seasons for six teams. He joined the San Francisco 49ers in 2010 as a seventh-round draft pick out of South Carolina State, and 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. Later, with the Oakland Raiders, he had two concussions over three games in 2012. 

Lesslie had been practicing medicine in Rock Hill since 1981, according to his bio page at Riverview House Calls & Riverview Hospice and Palliative Care, which he founded. He and his wife lived in Rock Hill with "their golden retriever, Moses, several miniature horses, goats, donkeys, chickens and a lot of bees", according to the page. It said he and his wife have four grown children and eight grandchildren.

On a recent blog that Lesslie had created, he posted what he said he had written more than 20 years ago on Valentine's Day, which he said is as true now as it was then:

"Valentine's Day. The American Heart Association has chosen this time of year to emphasize heart disease and its prevention. I suppose they're capitalizing on the symbol of this occasion. That's all well and good, and it's important.

"But today I want us to consider another type of heart trouble. I want us to think a minute about the uncertainty of life — about its frailty and about what really matters. Life is uncertain. Things happen. Lives are unexpectedly changed or ended. And it happens suddenly.''