Bernard Kerik, former New York City police commissioner and failed nominee to head the Department of Homeland Security, on Friday pleaded not guilty to federal corruption and tax fraud charges, which were announced in an unsealed indictment.

Kerik had surrendered to authorities earlier in the day, and entered his plea in federal district court shortly after noon.

• Click here to see the 29-page federal indictment of Bernard Kerik (.pdf).

In a news conference Friday with Justice Department and Internal Revenue Service officials, Kerik was painted as a man who used his position as New York's top cop, as well as the city jail commissioner, to gain financially. And officials said he lied to conceal shady dealings with mob-connected businessmen when he applied for his DHS job.

"It is a sad day when this office returns an indictment against a former law enforcement officer. Particularly one who served in positions as high as those held by Bernard Kerik. But we will not hesitate to pursue any public official who violates his oath and betrays the public trust as Mr. Kerik is alleged to have done," said Michael Garcia, U.S. Attorney for the Southern District of New York, speaking to reporters Friday.

"Nor can we tolerate lies to those who are given the critical task of vetting individuals for important public posts. Public service is a privilege," Garcia said.

Kerik faces 16 counts of interconnected charges stemming from shady business dealings and his nomination to the top DHS post.

"This is a battle," Kerik told reporters as he left the court after entering his plea. "I'm going to fight."

The indictment specifically charges him with receiving $255,000 in renovations to an apartment from a company seeking to do business with New York City. It charges him with multiple counts of false tax returns, including failing to report $236,000 in rent payments and $75,000 in income from a book.

It also charges him with:

— Taking $80,000 in phony charitable deductions.

— Failing to report wages for a domestic employee.

— Lying on a loan application for an apartment, and,

— Making multiple false statements in connection with his application to head DHS.

If convicted on all charges, he could face a maximum prison sentence of up to 142 years and $4.75 million in penalties.

"Moral relativism is not an appropriate yardstick for our public officials," said FBI Special Agent in Charge David Cardona, who spoke alongside other officials in announcing the indictment. "If a free cup of coffee is wrong, Kerik's long list of alleged crimes is repugnant."

Kerik is to be released on a $500,000 bond, which is secured by his New Jersey house. He was required to surrender all firearms, permits and licenses within 24 hours, and is not allowed to apply for new permits. He also must surrender his passport.

The judge also ordered Kerik to restrict travel to New York and New Jersey, and he must avoid contact with any government witnesses.

Federal prosecutors in New York have spent more than a year pursuing criminal charges against Kerik.

The indictment does not include any charges stemming from allegations of eavesdropping related to former Westchester County District Attorney Jeanine Pirro's pursuit of information about whether her husband was having an affair, an anonymous source told The Associated Press.

Prosecutors had been presenting evidence to a federal grand jury for several months, asking jurors to consider charges including tax evasion and corruption.

The investigation of Kerik, 52, arose from allegations that, while a city official, he accepted renovations to his Bronx apartment, paid for by a mob-connected construction company that sought his help in winning city contracts.

Former New York City mayor and presidential candidate Rudy Giuliani — who endorsed Kerik in 2004 to lead DHS before Kerik was forced to withdraw his nomination — has stood by his former business partner's record in New York, even though Giuliani said he should have checked his background more thoroughly.

"I have pointed out that I think I made a mistake of not checking him out more carefully. But when you balance that mistake against all of the successes that we had, and the reality that you make some mistakes and you make some correct decisions, I think the overwhelming record is a record of great success," Giuliani said Thursday morning during a campaign stop in Dubuque, Iowa.

Giuliani has said he does not know what implication the indictment would have on his campaign. His campaign declined to comment on the latest legal actions.

FOX News' Eric Shawn, Ian McCaleb and Mosheh Oinounou and The Associated Press contributed to this report.