The American computer hacker who shocked other Internet saboteurs by becoming an FBI informant didn't just break the law on the web: He also carried a gun and was involved in drug dealing.
Court documents unsealed this week show that in exchange for his help locking up fellow hackers, federal prosecutors agreed not to prosecute Hector Xavier Monsegur for a litany of other crimes he admitted committing, including illegal handgun possession and his attempted sale of a pound of marijuana in 2010 and 4 more pounds in 2003.
The court filings and other legal documents paint a picture of Monsegur, who was known on the Internet as a shadowy figure called "Sabu," as a chronic lawbreaker.
New York City's housing authority confirmed Friday that it recently obtained an eviction order tossing him out of his late grandmother's apartment in a public housing project, following two years of legal proceedings. In a statement, the agency said he "has not been a legal tenant in good standing."
Monsegur is also facing a month-old misdemeanor charge that he impersonated a federal agent.
The charge was filed shortly after an encounter between the hacker and a uniformed police officer at his building in the housing development on Feb. 3.
The officer said in a court complaint that when he asked Monsegur for identification, the hacker replied: "Relax. I'm a federal agent." The police officer then demanded to see a government ID. When Monsegur couldn't produce one, the officer checked with the FBI and was told that he didn't work for the bureau.
The officer signed a criminal complaint a week later. It's unclear whether the officer was aware at the time that Monsegur had, by then, been working as an FBI informant for months. It also isn't clear why the officer asked Monsegur for identification in the first place, although police routinely check the IDs of people leaving and entering city housing developments as a security measure.
In his court filing, the officer mentioned that Monsegur had referred to himself as "Boo," a possible mishearing of "Sabu," or a variation on the nickname.
Monsegur is due to make his initial court appearance on the complaint on March 12, but that hearing is expected to be postponed.
Court papers unsealed this week, and made public Friday, revealed that federal prosecutors have already agreed not to pursue charges against Monsegur for a variety of crimes, including gun possession, purchasing stolen jewelry and electronics, running up $15,000 on a former employer's credit card, referring people seeking prescription pain pills to illegal drug suppliers and hacking into the website of an online casino.
Monsegur signed the cooperation agreement on Aug. 15. By then, he had already been working closely with the FBI for two months, often pulling late hours exchanging messages with fellow hackers while federal agents watched.
The 28-year-old New Yorker, who operated from a sixth-floor apartment in the dilapidated Jacob Riis Houses, has already pleaded guilty to a string of computer crimes, including conspiring with the "hacktivist" groups Anonymous, Internet Feds and Lulzsec, and breaking into the websites of media and Internet security companies.
His cooperation with federal agents led to five arrests, announced this week, and the breakup of Lulzsec, a group he had helped create.
The court papers didn't name the former employer that Monsegur bilked for $15,000 in credit card charges. Monsegur has been unemployed since the spring of 2010. Before that, he worked for six months for OpenPlans, a nonprofit software development group founded by Mark Gorton, the same entrepreneur who created the file-sharing service Limewire, which was shut down in 2010 after a legal battle with the music industry.
Monsegur's deal with prosecutors could still leave him exposed to substantial jail time. The agreement, initially filed in secret last August, said he faced a minimum mandatory sentence of up to two years in jail, and more than 122 years in prison if a judge gave him the maximum punishment for every count.
His extensive work with the FBI, however, makes a harsh sentence like that extremely unlikely.
If Monsegur continues to work with the government, prosecutors agreed to dismiss many other charges against him, including allegations that he hacked into the computer systems at PayPal, Visa and Mastercard, attacked websites operated by the governments of Tunisia, Yemen, Algeria and Zimbabwe, and was involved in cyber assaults that attempted to cripple the websites of several global media and entertainment companies.
Lastly, the deal said that if Monsegur began fearing for his own safety, he might be enrolled in the federal witness protection program, and his "family and certain loved ones ... relocated under a new identity."
"It is understood that the defendant's truthful cooperation with this office is likely to reveal activities of certain individuals who might use violence, force and intimidation against the defendant, his family and loved ones," the agreement said.
Monsegur's lawyers have repeatedly declined requests for comment, and attempts to reach him have been unsuccessful.