Some lawyers call it "diesel therapy," bouncing an inmate from one prison to another to show them who's boss.

Imprisoned auto dealer Denny Hecker is getting a good dose.

Hecker, 59, was moved again Monday -- his fourth relocation in as many months -- with the latest journey taking him from a transfer facility in Oklahoma City to the U.S. Penitentiary in Canaan, Pa., 134 miles north of Philadelphia.

Joe Friedberg, a prominent Twin Cities defense attorney who is not affiliated with Hecker's case, described the diesel therapy approach: "That is when they have an inmate who is giving them problems and so they just keep them in motion, essentially just to teach them a lesson."

U.S. Bureau of Prisons spokesman Chris Burke declined to discuss Hecker's behavior, health or say where Hecker was going.

In February, Hecker was abruptly transferred out of a minimum-security prison camp in Duluth and sent to prisons in Wisconsin and Indiana. He was bused to an Oklahoma City transfer center last week and landed in Pennsylvania Monday.

Hecker, who is serving a 10-year prison sentence for fraud, allegedly violated phone privileges last year and may have been deemed a flight risk, his attorney has said.

Hecker isn't done moving yet. People familiar with the prison system and Hecker's case said Hecker's destination probably will be Loretto, Pa., which is 90 miles east of Pittsburgh.

Burke declined to discuss any possible move. But he confirmed that Loretto is a low-security facility with barbed wire fencing and a higher guard-to-prisoner ratio than Hecker had in Duluth.

Friedberg said Hecker's move to the Canaan prison Monday doesn't make sense for the long term.

"Canaan is probably too high a security level" for Hecker. But Loretto would make sense since it is just one security level higher than Duluth, Friedberg said.

Wherever Hecker ends up, Friedberg said, "he is not going back to minimum security. Hecker blew his chances for a [prison] camp."

"He was disciplined in Duluth for this issue with phones. And once he has done that, he has given up his privileges for a camp. They don't stand for that behavior."

William Michael, a former federal prosecutor who practices white-collar criminal law for the Chicago firm Mayer Brown, said prison authorities "are teaching [Hecker] that he is not above their system."

Constantly shifting his location is an "enforcement mechanism," Michael said.

Dan Scott, former federal public defender in Minnesota, said he is also familiar with the prison system's use of "diesel therapy," to ensure discipline among prisoners.

Misbehaving prisoners routinely get moved up and down the system.

"It's an effective way of defusing a problem," Scott said. "If you don't follow the rules you get moved farther away. It's a lot harder to get a visit when you are 1,000 miles away. ... Keeping order is awesomely important" in a prison setting.

Visits difficult

Hecker called long-time friend Ralph Thomas on Saturday and "sounded pretty down," Thomas said Tuesday. Hecker explained that he was being moved to yet another prison.

"Why are they moving him all around?" Thomas asked. "It's unbelievable."

The greater distance will deter some friends from going to see Hecker, Thomas said. "It is farther away. I am not saying I wouldn't go, but it is farther."

Burke at the Bureau of Prisons said he does not know how much Hecker's prison transfers cost the government.

He said the U.S. Marshal's office has an annual transportation budget. Officials from the marshal's office did not return phone calls seeking comment.

Brian Toder, Hecker's former attorney, has said previously that Hecker was moved out of Duluth because he may have been perceived as a flight risk.

In December, Hecker was put in special confinement away from the other prisoners in Duluth.

That was around the time his wife, Christi Rowan Hecker, was transferred from a women's prison in Illinois to a halfway house in the Twin Cities.

She was serving a 14-month sentence for bank fraud. She was released on probation in February after serving 12 months.

That's the same month Hecker was bused from Minnesota to Wisconsin and then Indiana.

Rowan, who did not return a phone call seeking comment, now lives in the Twin Cities with her two children.

Officials from the Bureau of Prisons and the U.S. Attorneys Office have declined to comment.

Star Tribune staff writer Paul McEnroe contributed to this report. Dee DePass • 612-673-7725 Dave Phelps • 612-673-7269