Triple murder case can't proceed until lab results are complete

Becky Campbell • Jul 26, 2018 at 5:42 PM

 A backlog of forensic tests at the Tennessee Bureau of Investigation crime lab was blamed Thursday for a lengthy delay in a triple homicide case in Washington County during a brief hearing for the defendant.

Derrick Benjamin Sells, 34, of Fall Branch, was scheduled for a motion hearing in Washington County Criminal Court, and the delayed test results were part of the reason the hearing was reset. Sells faces three counts of first-degree murder for the Dec. 4 shooting deaths of Kyanna Howes Vaughn, 23, and Robert Aaron Vaughn, 25, and their unborn child. The Vaughns were found by a friend who had been unable to reach them and went to check on them. The couple’s two small children were in the Friendship Court mobile home, but unharmed. Officials said Kyanna Vaughn was seven months pregnant at the time.

“We’ve filed some motions and we’ll have more,” defense attorney Steve Finney told Judge Lisa Rice. “Today we were just handed some ballistics.”

Assistant District Attorney General Erin McArdle had handed Finney and co-counsel Scott Shults a document, which was apparently a report from the TBI on evidence in the case.

McArdle told the judge there “may be more labs” and one more ballistic test the state hasn’t received yet. TBI Agent Scott Lott told the judge the lab has about a six-month backlog and he didn’t know where in that line of tests this case fell.

McArdle also asked Rice for an order to allow testing on two pieces of evidence — a syringe and a spoon — found in the car Sells was in when he was arrested. She said the tests would essentially destroy the evidence itself, and the lab wanted an order stating the defense agreed the testing could be done. 

Washington County sheriff’s investigators developed Sells as a suspect in the case, and he was arrested by Sullivan County Sheriff’s Office deputies Dec. 12 when he left his residence in Fall Branch. Sells was initially arrested on an outstanding violation of probation warrant in Sullivan County, but received new charges because authorities said he had a loaded weapon in the car. In addition to the weapon, Sells reportedly had clothing items that belonged to Robert Vaughn in his vehicle.

He was indicted by a special called Washington County grand jury Dec. 18 on three counts of first-degree murder, three counts of felony murder (murder in the commission of a felony), one count of aggravated robbery and two counts of aggravated child abuse/neglect.

Sells was initially represented by the public defender’s office, but a conflict developed and Finney and Shults were appointed. Prior to their appointment, Sells’ first attorney filed motions to restrict publicity in the case as well as a motion to allow Sells to wear street clothes during his court appearances.

Since then, Sells has appeared in regular clothing for his court hearings. On Thursday, he wore what appeared to be a cream colored linen suit and a yellow button-up shirt. His next motion hearing is Jan. 16, but there is also a status hearing on Nov. 8 to see if the lab tests results are completed.

Sells remains jailed on a $1 million bond while his case is pending.

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