As Rod Blagojevich begins serving his 14-year prison sentence in Colorado, a 1-time aide will learn his punishment for helping his old boss try to sell President Barack Obama's old Senate seat.

Unlike the ex-governor, former chief of staff John Harris started cooperating with investigators days after both were arrested Dec. 9, 2008. And he eventually pleaded guilty in an agreement with prosecutors.

Harris' cooperation included testifying for 10 days at Blagojevich's trials. That may mean Judge James Zagel shows him more leniency on Friday than he showed Blagojevich.

Prosecutors are expected to recommend a sentence of a few years. Defense attorneys say Harris should get probation.

The former state official launched a new career after his legal troubles, working as an apprentice on high power lines.