Phillip Adams, Former N.F.L. Player, Is Suspect in South Carolina Shooting

A doctor, his wife and two of their grandchildren were fatally shot in their house in Rock Hill, S.C., late Wednesday, and a fifth person was found dead outside, the police said

A neighbor of the family was found dead of a self-inflicted gunshot at a second home nearby, after a standoff with the police, who had been serving a search warrant, the authorities said.

The York County Coroner’s office on Thursday identified him as Phillip Adams, 32. Mr. Adams was a former professional football cornerback who was on the rosters of six teams over six seasons in the N.F.L.

The York County sheriff’s office, in a post on Twitter, identified four of the people killed as Dr. Robert Lesslie, his wife, Barbara, and two of their grandchildren. The coroner identified the children as Adah Lesslie, 9, and Noah Lesslie, 5. The website of a medical office where Dr. Lesslie, 70, worked said that he and his wife, 69, had eight grandchildren.

The fifth person who was fatally shot, James Lewis, 38, had been working at the home. He was found outside the home, the coroner said. A sixth victim was taken to a hospital with serious gunshot wounds, according to Trent Faris, a spokesman for the county sheriff.

Officer Faris told reporters on Thursday that the police had been serving a search warrant at the home, but his office declined to provide other details or confirm the suspect’s identity. “There is no active threat to the community,” county officials said in a statement on Facebook.

A man who identified himself as Mr. Adams’s father told a television station in Atlanta 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,” the man, Alonzo Adams, said. “I think the football messed him up. I don’t think he ever did anybody any harm.”

Alonzo Adams said he knew Dr. Lesslie and had even been his patient a “long time ago.”

“I know they were good folks down there,” he said. “I don’t know what happened or not. We’re going to keep them in our prayers. You all keep us in your prayers.”

A person who answered the phone at the sheriff’s office on Thursday morning said that no officers were available to comment further on the shootings. A news conference was scheduled for the afternoon.

A motive for the shooting was unknown. Officer Faris said there was no evidence of an accomplice.

Officer Faris said that Dr. Lesslie had been a prominent physician in the Rock Hill community and had started a local medical center. He had practiced medicine in Rock Hill, which is about 25 miles southwest of Charlotte, N.C., since 1981 and was a specialist in emergency medicine, according to the medical office where he worked.

The doctor had also been an active member of his church, a newspaper and magazine columnist, and the author of several nonfiction books about emergency medical workers.

“I view my medical career as an opportunity to go beyond simply diagnosing and treating individual patients,” he wrote on his website. “For me, it is a way to fulfill a higher calling by meeting the real physical and emotional needs of patients.”

Mr. Adams was born in South Carolina and played college football at South Carolina State University. A cornerback, he was drafted in the seventh round by the San Francisco 49ers in 2010. He played all but one game his rookie season, then split time between the New England Patriots and Seattle Seahawks in 2011. Adams spent the following two seasons with the Oakland Raiders. In 2012, he sustained two concussions within a three-game period.

Adams played his last two seasons with the Jets and the Atlanta Falcons. During his six-year career, he appeared in 78 games. He also was a punt returner, one of the most dangerous roles in football, in three of his six seasons.

It was not clear if Adams’ relatives would have his brain sent to researchers who could determine whether he had chronic traumatic encephalopathy, the degenerative brain disease associated with repeated head trauma. It has been associated with mood swings and outbursts.

The disease can be diagnosed only posthumously — a process that often takes months — though research by scientists at the Boston University School of Medicine has shown that memory loss and trouble focusing, following directions and handling everyday tasks are more useful at predicting C.T.E. than behavior symptoms.

Rock Hill, with a population of 67,000, is a small city where everyone knows one another. Officer Faris said Dr. Lesslie had been his childhood doctor.

“It doesn’t happen here,” he said. “So it’s one of those strange things that a lot of people are going to have a hard time understanding.”