UPDATE: Fall Branch man arrested in Washington County triple homicide

Becky Campbell • Updated Dec 18, 2017 at 6:25 PM

A specially convened grand jury indicted a Fall Branch man accused of gunning down a Washington County couple two weeks ago inside their Oak Grove-area residence, then leaving the couple’s two young children alone to fend for themselves.

Derrick Benjamin Sells, 33, of Fall Branch, was indicted Monday on three counts of felony first-degree murder, three counts of first-degree murder, unlawful possession of a weapon, especially aggravated robbery and aggravated child neglect.

Robert Aaron Vaughn, 25, and his wife, Kyanna Howes Vaughn, 23, were found dead around 7 p.m. Dec. 4 by friends who went to check on the couple. The Vaughns — married just a few months and expecting their first child together — were found shot to death inside their mobile home at 616 Friendship Court. Investigators said Kyanna Vaughn was approximately six months pregnant.

Sheriff Ed Graybeal reported that two children, ages 3 and 6, were found in the mobile home unharmed. There was evidence the older child, a boy, tried to feed his sister during the 24 or so hours they were alone, officials said.

District Attorney General Tony Clark said “at least one of the children was present” when the Vaughns were shot.

Graybeal and Clark made the announcement at an afternoon press conference Monday, just 30 minutes after Sells was picked up at the Sullivan County Detention Center by Washington County investigators.

Washington County and Tennessee Bureau of Investigation investigators developed Sells as a suspect in the Vaughn’s murders on Dec. 9 and set up surveillance on him with the assistance of Sullivan County law enforcement. Getting Sells in custody was a priority, Graybeal said. He contacted Clark about a special grand jury Monday.

They were friends

Graybeal described Sells as a friend of Robert Vaughn. He said cellphone records indicated the two had talked Dec. 3. Investigators believe Sells went to the Vaughns’ residence that night and killed the two.

The sheriff didn’t elaborate on the friendship or how close the two were. He said there were items missing from the Vaughn residence, but also would not disclose what they were, saying he didn’t want to jeopardize the continuing investigation.

Prior history

Sells was jailed last week in Blountville on a violation of probation warrant in Sullivan County. He was on the lam since that warrant was issued for his arrest in November 2016. Clark said he wasn’t sure if law enforcement attempted to locate Sells, and he didn’t fault Sullivan County for that, but said sentencing laws in Tennessee “stink.”

Sells was on probation after an arrest in January 2016 when he fled from a Kingsport police officer during a traffic stop.

Several hours later, Sells was arrested at his grandmother’s home on Rock Springs Road. The arrest was made after Sells tried to escape a K-9 officer, but the dog proved too much to fight off.

Ultimately, Sells pleaded guilty in May 2016 to those charges and received a three-year sentence suspended to supervised probation. His first violation was filed in November 2016, but he wasn’t arrested until last week.

Sells was pulled over by Sullivan County deputies on the violation, then charged with simple possession and possession of a firearm by a convicted felon when officers reported finding a loaded .357-caliber handgun in his vehicle.

After the arrest, investigators served a search warrant at Sells’ residence where “several items,” including weapons and clothing, were taken as evidence and sent for testing at the TBI crime lab.

Special grand jury

Clark said the last special grand jury called in Washington County was 15 years ago when Howard Hawk Willis was indicted.

“My office was contacted within an hour or so of when this happened,” Clark said. “I cannot say enough about the sheriff’s office … with the help of the TBI, they've been on this from day one.”

Clark said Tennessee law recognizes an unborn child as a person, which is why there are three murder charges.

“There was also felony murder during the commission of a theft, and there was the two child neglect charges. He left those children there with the parents, who had been killed, for at least 22 to 24 hours,” he said.

“I called the judge last week and she instructed the clerk’s office to go ahead and notify our grand jury. … We presented that case this morning. There was a true bill returned. I immediately walked that over to the judge and she set the $1 million bond.”

What’s next?

Clark said the next reporting date for recent grand jury indictments isn’t until Jan. 22, but he intends to ask a judge for a special court date for Sells to be arraigned on the murder charges. Clark said he has not had time to think about seeking the death penalty, but said there “are several criteria there that meets the elements of a death penalty case, but we’ve not looked at that yet.”

For now, Sells is in the Washington County Detention Center on $1 million bond, but he has no bond in the Sullivan County violation of probation case.

The Vaughns’ children are in state custody, but doing OK, investigators said. A fund was set up by the attorney appointed as the Guardian Ad Litem for the children to take donations. To donate to the fund, send checks payable to Michelle Caggiano, P.O. Box 5281, Johnson City, TN 37602 and use the reference number 17-1502. Information is also available by calling 423-207-6946.

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