As the public corruption probe known as “Polar Pen” continues to unravel, former state Senate President Ben Stevens apparently will not face criminal charges.

A newspaper article, relying on anonymous sources, says the U.S. Department of Justice has sent Stevens a letter ruling out an indictment against him.

It's unknown why federal prosecutors would drop the case, but they have suffered multiple and sometimes stunning setbacks since 2009.

Cliff Groh says he saw this one coming.

Groh, a lawyer who has served both as a prosecutor and a criminal defense attorney, has followed the polar pen investigation since it became public in 2006 on his blog Alaska Political Corruption.

While not offering an opinion on whether or not Ben Stevens broke the law, Groh says there are many reasons why the Department of Justice might have concluded they couldn't prosecute him.

"As one of my friends wrote me this morning, he said, 'Ben Stevens must have played hockey -- because he sure is good at skating."

Groh says Stevens' actual guilt or innocence might be irrelevant to the reasons behind the conclusion of the federal investigation into his conduct as a state senator.

"The investigation collapsed under the weight of the prosecutorial blunders that were revealed in the Ted Stevens case and later in the Kott and Kohring cases."

The late U.S. Senator Ted Stevens, Ben's father, was convicted on corruption charges in 2008 and lost his re-election bid, but the conviction was reversed when it was revealed that prosecutors didn't turn over evidence that could have helped the defense.

New trials for former state legislators Pete Kott and Vic Kohring have been ordered for similar reasons.

Meanwhile, two investigations of the investigators are under way, sidelining the prosecutors who knew the probe best.

"When prosecutors cheat, there should be ramifications,” said Rep. Les Gara, D-Anchorage, who has championed ethics reform in the wake of the public corruption probe. “So that has unfortunately maybe let some guilty people walk."

Groh continued: "Additional problems came out about the credibility of two of the prosecution's star witness, Bill Allen and Rick Smith, the well-known executives of the now-defunct oil services giant, Veco Corp."

And while videotapes played a key role in the trials of Kott and Kohring, it's unknown what showed up from Ben Stevens in 17,000 conversations that were captured by the FBI in the course of Polar Pen.

"It appears that Ben Stevens might not have played a prominent role doing dumb-looking and criminal-looking things on tape,” Groh said.

And Groh says that Stevens, unlike Kott and Kohring and former legislator Tom Anderson, made no attempt to conceal the money he was getting.

"The jury saw these clumsy attempts at concealment and they helped supply the criminal intent necessary under the law to convict them. For Ben Stevens, on the other hand, it was all hide in plain sight. He reported receiving more than $1 million as a legislator, almost $1 million in the five full calendar years he served as a state legislator from Veco and fishing interests alone."