ROCK HILL, S.C. -- Former NFL player Phillip Adams fatally shot five people, including a prominent doctor, his wife and their two grandchildren, before later killing himself, authorities said Thursday.

York County Sheriff Kevin Tolson told a news conference Thursday that investigators had not yet determined a motive in the mass shooting Wednesday.

"There's nothing right now that makes sense to any of us," Tolson said.

Dr. Robert Lesslie, 70, and his wife, Barbara, 69, were pronounced dead at the scene Wednesday, along with their grandchildren Adah Lesslie, 9, and Noah Lesslie, 5.

A man who had been working at the home, James Lewis, 38, from Gaston, was found shot to death outside. A sixth victim, Robert Shook, 38, of Cherryville, North Carolina, was flown to a Charlotte hospital, where he was in critical condition "fighting hard for his life,'' said a cousin, Heather Smith Thompson.

At Thursday's news conference, Tolson played audio of two 911 calls related to the shooting, the first from an HVAC company that employed Lewis and the other person doing work at the Lesslie home. One of them, the caller said, had called him "screaming" and saying that he had been shot and that his co-worker was shot and "unresponsive."

"I think there's been a bad shooting," a different man said in a second 911 call, saying he was outside cutting his grass and heard "about 20" shots fired at the Lesslie home before seeing someone leave the house.

Tolson said evidence left at the scene of the shooting led them to Adams as a suspect. He said they went to Adams' parents' home, evacuated them and then tried to talk Adams out of the house. Eventually, they found him dead of a single gunshot wound to the head in a bedroom, he said. Adams was 32.

Tolson said both a .45 and a 9mm handgun were used in Wednesday's shooting.

Adams had been treated by Lesslie, who lived near his parents' home in Rock Hill, according to a person who was briefed about the investigation and who spoke on condition of anonymity because he wasn't authorized to speak publicly.

However, Tolson would not confirm that Adams had been the doctor's patient.

Lesslie had worked for decades as an emergency room doctor, board-certified in both emergency medicine and occupational medicine and serving as emergency department medical director for nearly 15 years at Rock Hill General Hospital, according to his website.

A biography page said he and his wife raised four children and were actively involved with their church, as well as with Camp Joy, which works with children with disabilities, and where Lesslie served as camp physician for a week each summer. On Thursday, Tolson said the family had asked that any memorials be made to the organization.

Adams played in 78 NFL games over six seasons for six teams. He joined the 49ers in 2010 as a seventh-round draft pick out of South Carolina State, 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 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 the leg. He never played for the 49ers again, getting released just before the 2011 season began. Later, with the Raiders, he had two concussions over three games in 2012.

Whether he suffered long-lasting concussion-related injuries wasn't immediately clear. Adams would not have been eligible for testing as part of a broad settlement between the league and its former players over such injuries, because he hadn't retired by 2014.

Adams' father told a Charlotte television station that he blamed football for problems that might have led his son to commit Wednesday's violence.

"I can say he's a good kid -- he was a good kid, and I think the football messed him up," Alonzo Adams told WCNC-TV. "He didn't talk much and he didn't bother nobody."

Deputies were called around 4:45 p.m. Wednesday to the Lesslies' home, which is far up a driveway from an arched stone gate, and not visible from the road. They evacuated the neighbors as they spent hours searching for a suspect with police dogs.

Allison Hope, who lives across from the Adams' modest one-story brick home, about a mile down the road from the Lesslies, said police allowed her to return home around 9 p.m. Wednesday. Moments later, a vehicle pulled into their driveway and law enforcement quickly surrounded the property.

She said they spent hours negotiating with Adams, using a loudspeaker and sending in a robot to scan the house. She said authorities repeatedly asked Adams to come out, and promised to get his disabled mother out safely, before Adams shot himself.

"This is something I can't grasp yet. I can't put it all together and I'm trying to, and I witnessed it," Hope said. "I feel bad for him because if it was mental or something going on in his life or whatever, you know, he needed help, and that's the sad part."

Adams often isolated himself, even as a player, his agent, Scott Casterline, told the Associated Press. Casterline said he spoke regularly with Adams' father, who left him a voicemail Wednesday morning.

"He was part of my family. I loved him. He's a great kid, a great guy. This is so unlike him. He had to not be in his right mind, obviously," Casterline said.

"All of us who knew Philip are shaking our heads. He struggled away from the game. I tried to get him to come to Texas. I was going to find him a job, but he wouldn't leave South Carolina because he had a son. He was a good father.

"Seeing Philip shoot two kids, it's not him. I can't fathom it. It's devastating for the victims and the families," Casterline said.

Former Cowboys cornerback Kevin Smith, who trained Adams leading up to the 2010 draft and after he entered the league, said he was a hard worker. He and Casterline both said Adams had opened a shop selling smoothies and juice before COVID-19 hit, and they emphasized Adams didn't drink or do drugs.

"He didn't drink not one bit of alcohol," Smith said. "He was a bit of a neat freak. In his house, everything was precisely placed."

Lesslie founded two urgent care centers, wrote a weekly medical column for The Charlotte Observer and became a prolific author, writing several volumes with advice on how to lower cholesterol or blood pressure and lose weight. The physician also penned a number of collections of what he termed "inspiring true stories" from his work.

"I know without a doubt that life is fragile," Lesslie wrote in one of those books, "Angels in the ER."

"I have come to understand that humility may be the greatest virtue. And I am convinced we need to take the time to say the things we deeply feel to the people we deeply care about."

Reading a statement from the Lesslie family, Tolson said the family was "in the midst of the unimaginable" but felt assured by faith that their "hearts are bent toward forgiveness and peace."