NASHVILLE, Tenn. -- A convicted sex offender who is hundreds of miles away from Nashville has found himself ensnared in the case of accused serial killer Bruce Mendenhall.

Video: Indiana Sex Offender Connected To Accused Serial Killer

The Channel 4 I-team has learned that two Nashville detectives traveled to Anderson, Ind., earlier this week to interview 24-year-old David Powell.

Powell once dated Mendenhall's daughter in Illinois, according to Indiana detectives, but apparently Mendenhall wasn't pleased with the relationship.

"There was comment made by Mr. Mendenhall, according to Mr. Powell, that 'If you ever harm her or do something to her I will kill you,'" said Detective Kris Ockomon of the Anderson, Ind., Police Department.

Indiana police said Mendenhall implicated Powell as among those who helped commit the murders. Powell gave a DNA sample but denies any recent connection to Mendenhall.

"According to Mr. Powell, he had not seen nor had any conversation with Mendenhall for approximately four years," said Ockomon.

Powell's background also made him suspicious to police. He is a registered sex offender in Indiana, but the I-team has learned when Powell dated Mendenhall's daughter in Illinois, Powell failed to registered as a sex offender and has a felony warrant there for his arrest.

But as of now, authorities said Powell is only a person of interest in the Mendenhall case and was questioned and released.

Indiana police said another man from Anderson, Ind., Terry Sanders, was also questioned and released by police.

Indiana authorities said a third individual is being sought for questioning. Nashville police are not yet commenting on this portion of the investigation.

Accused Serial Killer Waives Right To Hearing

The Illinois truck driver waived his right to preliminary hearing in Nashville on Thursday and his case will go straight to a grand jury.

Video: Mendenhall Makes Appearance At Hearing

That prevented the prosecution from presenting any evidence against Mendenhall. Few details about his alleged crimes have been revealed beyond the first affidavit filed soon after he was arrested on July 12 and charged in the murder of a woman in Nashville.

The hearing was meant to determine whether there is enough evidence to keep Bruce Mendenhall in jail, where he is being held without bond.

His public defender, Amy Harwell, declined to say why he had waived his right to the hearing or otherwise comment on the case.

Mendenhall, 56, kept his head down as he appeared briefly in Davidson County General Sessions Court wearing khakis, a blue oxford shirt and shackled at the ankles. His responses to the judge's questions were mumbled and inaudible to those sitting in gallery of the courtroom.

Mendenhall was charged with criminal homicide last month after being questioned by police at the same north Nashville truck stop where Sara Nicole Hulbert, 25, was found dead with gunshot wounds on June 26.

Police say he implicated himself in Hulbert's death and at least five other similar slayings of alleged prostitutes at truck stops in Tennessee, Alabama, Georgia and Indiana when they first interviewed him. He has refused to talk to police since that time, a detective has said.

The affidavit in the Nashville case states that Mendenhall's truck matched a description of a truck seen the night Hulbert was killed. Inside the truck police found what appeared to be blood on the inside of the driver's door, inside a trash bag behind the driver's seat and on Mendenhall's left thumb.

At a subsequent press conference, a spokeswoman for the Tennessee Bureau of Investigation stated that the agency had retrieved hundreds of pieces of evidence from the truck but declined to describe them.

Mendenhall was also charged last week with killing Lucille "Gretna" Carter in Birmingham, Ala.

Investigators said the 44-year-old transient was shot and dumped nude next to a trash bin on a service road. She was found July 1 with a plastic bag over her head and duct tape around her neck. Mendenhall has not been charged in any of the other cases.

Law enforcement agencies across the country have contacted Nashville investigators to learn if Mendenhall could be involved in unsolved murders in their areas. The FBI has been creating a timeline of Mendenhall's travels during his 20 years as a trucker to determine other cases in which he could be a suspect.

Relatives of Hulbert, who had two young children, appeared at the courthouse.

"We hope that this comes to an end soon," said Roxanna Wayman, Hulbert's sister. "And we are glad that if Bruce Mendenhall is convicted of these crimes, he will not be allowed to be back on the streets to do this to any other victim and no other family will have to go through what our family has endured."