Parents upset their teens were forced to give statements in the slaying of a popular teen have filed a federal lawsuit against the Douglas County Sheriff's Office.

The parents said deputies violated the civil rights of their children by placing them on a prisoner transport bus for hours while they took statements and investigated the beating death of 18-year-old Bobby Tillman during a high school party at a private home.

"It was tormenting. I didn't know where my son was that night," Jessica Washington said. She is one of four parents named in the lawsuit.

Washington said she had no clue deputies had taken her son, Derrick White, 15, from a party, placed him on a prisoner transport bus, and took him and about 60 other teens to the sheriff's office for questioning.

Her attorney said some of the teens were held for about 10 hours.

Washington said a deputy guarding the bus turned her away when she found out he was at the sheriff's office.

"And I said 'I need to see if my son is on this bus.' And he said, 'I can't tell you if your son is on the bus,'" Washington said.

Channel 2's Tom Jones was at the Richard Russell Federal Courthouse on Wednesday when the parents and their attorneys filed the lawsuit.

Their attorney, Sandra Dawson, said the public needs to know what happened that night.

"And there are claims that these children were mistreated and their rights were violated," Dawson said.

Dawson said the teens weren't given food or water, and weren't allowed to go to the bathroom. She said parents should have been asked to give permission for deputies to take their children's statements.

But the lead investigator on the case said that's not true.

"If he's a witness in a case, you don't have to contact a parent," explained Lt. Bruce Ferguson of the Douglas County Sheriff's Office.

Ferguson makes no apologies for gathering all the teens at the party on a bus and taking them to the sheriff's office for questioning.

"If I had let everyone of those kids go I could still be trying to track down witnesses and trying to interview them in this case. We did it pretty much in one night," Ferguson said.

Ferguson said the teens' rights weren't violated. He said they were given water and were allowed to go to the bathroom. Ferguson said they were held no longer than four hours, but deputies did collect their cellphones.

"We took the phones to see if anybody had video ... took pictures of it," Ferguson said.

Ferguson said his tactics worked because of where he found one of the suspects.

"One person on the bus and the fourth person turned themselves in that evening," he explained.

Four people have been charged with Tillman's death.

Tillman's mother said her family supports what the sheriff's office did that night.