HOUSTON -- A death row inmate who escaped from a downtown Houston jail remained on the loose Friday, as deputies feared trial witnesses in his case could become victims of retaliation, KPRC Local 2 reported.

Charles Thompson, 35, was convicted of killing his ex-girlfriend and her boyfriend in 1998.

Officials with the Texas Department of Criminal Justice informed the murder victims' relatives and witnesses shortly after authorities said Thompson walked out of Harris County Jail's Baker Street facility at about 3:30 p.m. Thursday.

Officials told KPRC Local 2 that he was transferred from death row to the Harris County Jail on Thursday for a court appearance. While there, he persuaded guards to let him out of his cell for an attorney visit. Authorities believe that was one of two ruses he used to escape.

"This is 100 percent human error. It's not like he defeated a locking mechanism or broke a hole in a wall. He convinced people to essentially let him out," Harris County Sheriff's Department Lt. John Martin said.

Authorities said Thompson used a fake badge and a change of clothes to disguise himself as an attorney to elude workers and escape from the jail.

"Apparently he smuggled those items back to his jail cell after his (last) court appearance. He did have an attorney visit (Thursday) at approximately 1:45 in the afternoon. While he was in the attorney booth, he got out of his inmate jumpsuit -- the orange clothing they commonly wear -- changed into civilian clothing," Martin said. "What we've found is that he either put his jumpsuit over his clothing or put the clothes in with his legal papers when he came back to the jail."

Martin said Thompson then got out of a set of handcuffs, left the locked interview booth and made it through three security doors. He convinced deputies he was an attorney with the attorney general's office.

"The only association he had with the attorney general's office were the comments that he made to the deputies, so, at this point, there is no indication that the card itself actually identified him as being with the attorney general's office."

KPRC Local 2 has also learned that the fake badge Thompson showed jail workers had his picture on it.

"At no time did (officials) actually have it in their hands where they could really closely scrutinize this badge," Martin said. "It was a laminated card, like a driver's license or something of that nature. He told the (floor control) deputy that he was with the attorney general's office and that he was conducting an investigation inside our jail."

Martin said that Thompson's escape was discovered almost immediately.

"We have a large investigation under way by our internal affairs division. Everybody who may have either come into contact with this individual or just may have information about the escape will be questioned about it," he said.

Thompson Has Violent Past

Thompson was caught trying to hire a hit man to kill a prosecutorial witness in his murder trial, which is why authorities believe he could target witnesses again.

"My understanding is they were notified very early yesterday when this happened by TDCJ personnel so they are well aware of it and extremely concerned. The fear is that he could seek retaliation against them," Martin said.

Thompson calls himself the "Chuckster Killer" and has planned two murder-for-hire plots for trial witnesses from his jail cell. Authorities believe he could act on those plots because he has nothing to lose.

"He has been twice sentenced to death, and he has absolutely no incentive to cooperate with law enforcement," Martin said.

Thompson kicked in the door of Dennise Hayslip's north Harris County apartment in April 1998. Her boyfriend at the time, Darren Cain, was also inside the apartment when Thompson opened fire on them. They were pronounced dead at the scene.

Hayslip's mother is worried for her safety.

"The fact that he just walked out, it's unbelievable," Wynona Donaghy said. "I know what he is capable of. And I know that he has made threats against a lot of different people and now that he's free and can do it on his own, he doesn't have to hire it done. I don't know how far his list will go."

The Texas Court of Criminal Appeals upheld Thompson's convictions last Friday and was sentenced to death a second time for the murders of Hayslip and Cain.

Authorities said they are not sure if Thompson had help in his escape, but said it was well planned and executed.

Every law enforcement agency in the area is on the lookout for Thompson. Authorities consider Thompson extremely dangerous and say he should not be approached if spotted.

Thompson is a white man, 5 feet 10 inches tall and weighs more than 200 pounds. He was last seen wearing khaki pants, a dark blue shirt and white tennis shoes before escaping the jail.

Anyone with information is asked to contact the Harris County Sheriff's Office at (713) 221-6000, the Criminal Warrants Division at (713) 755-6055 or 911, the Criminal Warrants Division at (713) 755-6055 or 911.