Former NYPD top cop Bernard Kerik has reported to a prison in Maryland to begin a four-year sentence.
Kerik pleaded guilty in November to tax fraud, lying to the White House and other criminal charges.
Bureau of Prison spokeswoman Felicia Ponce said Kerik surrendered at about 1:45 p.m. Monday at the Federal Correctional Institution in Cumberland, Md.
In a statement dated Sunday on his website, the former 9/11 hero said he could not remain silent "in the face of what I believe has been a grave injustice." He said he pleaded guilty to eight felonies in November because he was "financially helpless" and could have spent a year behind bars just awaiting trial.
Kerik's steely resolve as he stood with his mentor, Mayor Rudolph Giuliani, won him worldwide fame after the 2001 terror attacks. His career peaked three years later when he was nominated by President George W. Bush to lead the Department of Homeland Security.
While he was being vetted, however, questions were raised about his finances and associations, and he bowed out of the nomination. He later admitted in court that he lied when he denied having any financial dealings with anyone doing business with New York City.
When he was sentenced in February, federal Judge Stephen Robinson said Kerik had used 9/11 "for personal gain and aggrandizement." The judge went beyond federal sentencing guidelines, which suggested two to three years in prison, because of what he called "the almost operatic proportions of this case."
Kerik's new statement expressed disappointment with the judge, the prosecutors and the sentence and said he hoped it would be "remedied by an appellate court."
He said he hoped God would return him to his wife and his 7- and 10-year-old daughters "much sooner rather than later."
Kerik said he watched the movie "Rocky Balboa" with his daughters to illustrate "the principles of courage, strength and perseverance."
He said he told the girls, "It is time to move forward."
After his sentencing, Kerik apologized to the nation and said he hoped history would take into account the "30 years of service I've given to the country and the city of New York."
In a television interview last month, Kerik said he stopped speaking with Giuliani in 2006, as the former mayor began running for president, to protect him. He added, however, "We will be friends for life."