This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

Please enable Javascript to watch this video

CHESTER, Ill. -- It was four years ago Tuesday that former Bolingbrook cop Drew Peterson was sentenced to 38 years for the murder of his third wife, Kathleen Savio. Suspected in the disappearance of another wife, Peterson had another 40 years tacked on for ordering a hit on the prosecutor who put him away.

Tuesday he was moved from a state prison downstate to a federal lockup in Terre Haute, IN, and no one knows why. Not even his lawyer Steven Greenberg.

“I’m as befuddled as anybody...I’ve never seen this before," Greenberg said. "I don’t know why they would move him to federal custody."

Greenberg said he learned about the transfer of his infamous, long-time client when WGN asked why it was happening. Later, after learning there was no new charge- not state, not federal- he said there was no discernible reason for a transfer from state to federal custody.

Drew Peterson was serving a 38-year sentence at the Menard Correctional Center in downstate Illinois for the murder of his third wife Kathleen Savio.

Last year, Peterson was also convicted of plotting to murder the prosecutor who put him in prison, Will County State’s Attorney James Glasgow. That conviction carries with it an additional 40-year prison term.

A former Bolingbrook police officer, Peterson gained instant notoriety nine years ago, when his pretty and popular young wife Stacy simply vanished. He could not stay away from the attention or from cameras that followed him.

The fact that Stacy, his fourth wife, had vanished without a trace vexed investigators enough, even ignoring the fact that his third wife, Kathleen Savio had died under questionable circumstances. That case got a closer look, and Drew Peterson eventually went to prison based on a law designed for him alone.

Even behind bars, he courted the spotlight after investigators learned he was looking for vengeance against the man who put him away. Peterson tried to hire a hitman to take out Will County State’s Attorney Jim Glasgow, an act that only added four more decades to his time behind bars.

Even after that he did not go quietly, and a WGN Investigation revealing taxpayers had shelled-out hundreds of thousands of dollars for his defense in the murder-for-hire case.

The disappearance of Peterson’s fourth wife, Stacy Peterson, remains unsolved. The Will County State’s Attorney says the prisoner transfer has nothing at all to do with the ongoing Stacy Peterson investigation.

Stacy's family said they didn't know anything either through their spokesperson. In fact, they too have been learning a lot of the details through the media, and said they’re trying to keep the search for answers in Stacy’s disappearance alive. That includes a physical search relatives have been planning for next weekend, which is still going ahead.

Lawyer Greenberg said he spoke to Peterson just a few days ago, and was completely caught off guard.

"He was in good spirits; he didn’t tell me anything was going on; I didn’t suspect anything was going on," Greenberg said. "I sent him a letter last Tuesday or Wednesday, and I sent the letter to Menard."

But Peterson was already gone, and no one seems to know why.

37.913663 -89.82205