KNOXVILLE, Tenn. -

A man wanted in connection with a triple murder in Central Florida has died after being taken into custody Tuesday afternoon in Tennessee, officials said.

David Eugene Smith, 27, was taken to a hospital with a self-inflicted gunshot wound following a SWAT standoff at a Days Inn in Knoxville, according to officials.

Knox County Sheriff's Office said Smith had died just after 5:30 p.m. at the UT Medical Center. An autopsy for Smith is scheduled for Wednesday.

Polk County Sheriff Grady Judd said earlier in the day that Smith shot and killed three people, including his sister, at a home on Old Highway 37 near Lakeland.

"We found him," Judd said earlier, referring to the SWAT standoff in Knoxville.

Judd said a 14-year-old ROTC student returned from a weekend event Monday night and found her mother's body in their Polk County home.  Authorities were alerted and the other two bodies, a man and a woman, were found inside the home.

"It was a very violent scene," said Judd, who added that the triple slaying could have occurred as early as Saturday night.

Judd identified the victims as David's sister, Danyala Smith, who was the teen's mother; Ni'Kosi Williams, of Lakeland; and 28-year-old Miranda Mims, a friend of Danyala.

Judd said Smith, who goes by the name Davey, has a history of mental illness, adding that Smith is paranoid and delusional.  Smith's mother said her son served in the Army and had tours in Iraq and Afghanistan and suffers from PTSD.

Detectives were told that Smith refers to himself as "Prince David." Judd said Smith had posted, "I hate evil and will not allow it on my planet," on his Facebook page.

"We fear for the community until we find this man," Judd said earlier Tuesday morning in a news conference.  "This suspect has taken the lives of three people and we need to find him before he harms anyone else."

The SWAT team in Knoxville launched tear gas into Smith's hotel room and took Smith down. Smith shot himself in the arm, Tennessee authorities said, indicating that he wanted to commit suicide.

According to jail records, Smith was arrested in 2009 on charges of cocaine possession, carrying a concealed weapon (firearm), marijuana possession and narcotic equipment possession.  The firearm and cocaine possession charges were dropped, however.

Judd also said that Smith was taken into custody under the Baker Act, or the Florida Mental Health Act, by local police once before.

Judd said the 14-year-old girl who found her mother dead is doing as well as can be expected.

"I consider her exceptionally lucky she wasn't in the house this weekend," Judd said. "At that point in time, he killed everyone in the house, and he wouldn't have spared her life if she wasn't in the house."