Trucker With Traveling Torture Chamber Admits to More Murders Robert Ben Rhoades will serve two life sentences without parole.

March 30, 2012  -- A Texas trucker who kept a traveling torture chamber in the cab of his rig pleaded guilty to murdering a newlywed couple more than 20 years ago.

Robert Ben Rhoades, 66, is already serving a life sentence without parole for the 1990 murder of 14-year-old runaway Regina Walters in Illinois.

Prosecutors say the trucker kept a mobile torture chamber in the cab of his long-haul rig.

"There's this compartment that's hidden completely from view other than between the seats," Steve Smith, first assistant for the 112th District Attorney's office in Texas, told ABCNews.com.

The dungeon-like compartment was described in "Roadside Prey" by Alva Busch, a book written about Rhoades. The rig was equipped with handcuffs on the ceiling, which enabled Rhoades to chain his female victims so that he could torture them before killing them.

Prosecutors believe Rhoades may have put many other women through the cycle of "kidnap, torture, and kill," but Smith said they do not know how many women he may have hurt, since he traveled so much.

"That was the problem with him," Smith said. "He was on the interstate everywhere."

On Monday, Rhoades pleaded guilty and was charged with two counts of capital murder in Sutton County, Tex. for the slayings of Patricia Walsh, 24, and her husband Douglas Scott Zyskowski, 28.

Rhoades received a second life sentence in the plea, in exchange for prosecutors not seeking the death penalty.

"The defendant essentially agreed to stack the life sentences in Illinois, which means he'll never get out," Smith said. "He's 67. He will die in prison."

Rhoades has spent the past few years in a Texas prison, but will soon be sent back to Illinois to serve the life sentences. Smith said that should Rhoades ever be released from the Illinois prison for any unforeseen reason, he would be returned to a Texas prison.

"I've been a prosecutor since 1979 and it was one of the rare occasions when I was in the court where the defendant walked in and you felt the evil," Smith said. "The hairs on my arm stand up right now talking about it."

Walsh and Zyskowski, the newlywed victims, left Seattle in November 1989 to hitchhike to Georgia where they were going to preach the Christian gospel when Rhoades picked them up in Texas.

Smith said prosecutors believe Rhoades killed Zyskowski relatively soon after picking him up and dumped his body along Interstate 10 in Ozona, Texas. The body was found in 1990, but not identified until 1992.

Walsh's remains were found in October 1990 in central Utah, but not identified until 2003, with the help of dental records.

"Her body was found months later so she was probably kept alive for a while," Smith said.

Prosecutors believe Rhoades may have put many other women through the cycle of "kidnap, torture, and kill," but Smith said they do not know how many, since he traveled so much.

"That was the problem with him," Smith said. "He was on the interstate everywhere."

Rhoades' attorneys did not respond to requests for comment from ABCNews.com.