Brian David Mitchell and a murderous polygamous family patriarch shared many similar traits and operated in very similar ways, an expert on religious cults and their members who commit crimes testified Wednesday.

Richard Forbes, a retired law enforcer for both Salt Lake and Los Angeles counties, investigated killers Ervil LeBaron and Charles Manson during his career. Forbes is an expert on LeBaron and his followers.

During the third day of Mitchell's competency hearing in federal court, Forbes compared the man accused of kidnapping and raping Elizabeth Smart to LeBaron and other religious cult leaders.

Both men used revelation as a tool to get what they wanted, Forbes said.

"He basically used the same type of revelations that Ervil did," Forbes said of Mitchell. "They're very similar in that Brian David used revelations to control the movements of him, his wife and Elizabeth Smart. I think he used the excuse of a revelation to get people to do things he didn't want to do."

In comparing the two figures, Forbes noted that Mitchell and LeBaron were both raised in LDS environments; were later excommunicated from The Church of Jesus Christ of Latter-day Saints but continued to maintain a belief in church founder Joseph Smith and his teachings; and controlled those around them by using their own interpretations of revelations and threats of death.

Many times during Smart's nine-month captivity, Mitchell threatened to kill her and her family if she tried to escape, Forbes said. LeBaron often actually followed through on his threats.

LeBaron is believed to have been responsible for the murders of more than 20 people, mainly former followers, in several states, including Texas and Utah. He was convicted of orchestrating the murder of an opponent and sentenced to the Utah State Prison, where he died in 1981. LeBaron was never determined to be incompetent to stand trial.

Forbes also said both men claimed to be "the one mighty and strong," which he said is a common claim among cult leaders.

He compared Mitchell's "Book of Immanuel David Isaiah" with LeBaron's "Book of the New Covenant." In both sets of religious writings, each man claims he received the keys from God to lead people out of a corrupt society, Forbes said. Whereas Mitchell referred to himself as a prophet, LeBaron called himself, among other things, the third part of the Holy Trinity or the Holy Ghost, the "mouthpiece of God" and the "foremost man who now helps people shape up."

Both Mitchell and LeBaron violated the "rules of man" that prohibit crimes including killings and rapes and kidnappings, but both men justified their actions because they believed they were given the authority by God to do so, Forbes testified.

He also compared characteristics of the way Mitchell and LeBaron acted with the operation of cults such as Heaven's Gate, as well as others led by Manson, David Koresh and Jim Jones. Such cults used persuasive recruitment, isolation techniques to separate recruits from their environments and families, and indoctrination.

One of the ways Forbes noted that Mitchell was different from LeBaron, however, was that Mitchell forced people, such as Smart, into his group.

Wednesday's hearing started with an FBI agent who interviewed Mitchell on four different occasions in the days immediately following his arrest in 2003.

Special agent George Dougherty said Mitchell was calculated in his answers and seemed to have an understanding of the legal system or could process enough information that he understood what he was being told.

During one interview, Mitchell "wanted to know what the next step was" in the legal proceedings against him, Dougherty said.

When the agent asked about the kidnapping, he said Mitchell told him, "She was able to return anytime she wanted to."

Dougherty said Mitchell also told him that he gave Smart and his now-estranged wife and co-defendant Wanda Barzee "instructions about what to say" if they were caught. He also noted that in the days immediately following the kidnapping when Mitchell took Smart to his campsite in the foothills, "They could easily hear the people searching in the mountains behind the Smart family house," Dougherty said.

Dougherty followed up by asking if Smart was bound and gagged.

"She was never gagged," he said was Mitchell's answer but later added, "She was bound by her false traditions of society."

"He was very calculated about how he answered the questions, like he was on a witness stand," Dougherty said.

Sandy police detective Troy Rassmussen was one of the first police officers to talk to Smart, Mitchell and Barzee when they were walking along State Street on the day that she was found. Mitchell tried to deceive police by lying about his name and the names of Smart and Barzee.

"I think he was being deceptive. The more I cornered him in his lies, he would be a street preacher," meaning he broke out into religious conversations, Rassmussen said.

Also Wednesday, another Utah State Hospital employee took the stand testifying that Mitchell's behavior in court was different from when he was at the hospital.

Brigham Andrew, a senior psychiatric technician at the hospital, was an employee during both of Mitchell's hospital stays. Andrew said that compared to the way other patients in the hospital acted, he was surprised to see Mitchell return a second time.

"My first impression was, 'Why did he come back?' My impression was he was competent and should not be at the state hospital," Andrew said. "There was nothing in his behavior that was incompetent."

Two U.S. deputy marshals who have transported Mitchell from jail to the courthouse testified that Mitchell's demeanor is different when he doesn't believe he's being observed.

Whereas Mitchell will ignore a judge's request to stop singing and be removed from the courtroom, deputies Dan Juergens and Jon Burnett testified that Mitchell rarely ever gave them trouble and would stop singing when they asked him to stop.

"When we need him to pay attention, he'll stop singing," Juergens said.

Mitchell is mostly compliant when he's in a holding cell or being transported to the courthouse from jail, the marshals testified.

The one day Mitchell did not want to cooperate, however, was in October, when Smart delivered her testimony for the competency hearing.

When he was picked up at the Salt Lake County Jail to be transported to the courthouse for the hearing, Mitchell yelled, "Repent, repent," Juergens testified. When he reached the courthouse, he refused to speak to his attorneys or even meet with them. "No visitors," was the message Mitchell had the marshal relay to his defense team.

Mitchell was removed from court again Wednesday when he refused U.S. District Judge Dale Kimball's order to stop singing.

Smart was 14 when she was kidnapped from her Salt Lake bedroom on June 5, 2002. She, Mitchell and Barzee were spotted in Sandy in March 2003, just a week after the trio had left Lakeside, Calif. Mitchell and Barzee were arrested and charged both in state court and federal court.

Mitchell's 10-day competency hearing was scheduled to go until Dec. 11.

Two key witnesses, the final two on the government's list, were expected to testify Thursday and Friday. Dr. Noel Gardner, who twice found Mitchell to be competent during his state competency hearings, and Dr. Michael Welner, who prepared a 206-page report concluding Mitchell was competent, were expected to be called to the stand this week.