Justin Volpe – the cop involved in one of the most sensational police-brutality cases in city history – has asked for a commutation of his 30-year prison sentence from President Bush.

The 36-year-old ex-cop, who notoriously used a broomstick in a precinct station house to sodomize victim Abner Louima, has sent a formal request – along with a small mound of letters of support – to the Justice Department’s Office of the Pardon Attorney, which handles referrals to the president for rare reductions of sentences.

Volpe has been behind bars for about 12 years without chance of parole. He is set to be released from a Minnesota federal prison in 2025.

The former officer got support for his application at the Holy Child Church on Staten Island, where his family members are parishioners.

In a recent letter to the congregation in support of Volpe, the church’s pastor, Father Travers, noted that a “commutation is a reduction” of a penalty and “not an exemption or a pardon or an excuse.

“We all know that some people guilty of taking human life serve far less time than 30 years,” the priest wrote. “And if they are not in the federal system, they may have the possibility of parole.”

Volpe’s mother, Grace, a schoolteacher, said her son hoped that his application for commutation would go unnoticed by the media and that she would have no other comment.

But one of the family’s supporters explained why she was behind the request.

“Just[in] was a wonderful kid who used to feed the homeless on Thanksgiving. What happened that day was 30 seconds of something that was unspeakable, horrible. But isn’t 12 years enough?” asked the woman, who asked not to be identified.

In the case that shocked the city, Volpe admitted that he assaulted a handcuffed Louima in a sudden fit of rage inside a Brooklyn precinct after a street confrontation in 1997.

Louima, a Haitian immigrant, accepted a $8.7 million settlement from the city and police union and is living in Miami.

The judge sentenced Volpe to the 30 years without parole under a federal guideline that allows harsher penalties for cops than for ordinary citizens.

New York officials say the average incarceration of a violent offender in state prison is 7 ½ years.

Cold-blooded murderers serve an average 24 years. First-degree manslaughter convicts serve about 12 years, while murderers found guilty of second-degree-manslaughter spend only an average of 6.6 years in jail. Other killers, however, serve little more than three.

At his sentencing, Volpe tearfully declared he was “still ashamed” and then apologized to Louima, the city and the NYPD for the betrayal of their trust.

Since then, Volpe has been a model inmate, doing art – his late father, Robert, was a legendary NYPD “Art Cop” investigating stolen masterpieces – and reading literature and religious works.

murray.weiss@nypost.com