CHICAGO (CBS) — Federal prosecutors are seeking a maximum 10-year prison sentence for Thaddeus “T.J.” Jimenez, who became a multimillionaire in a wrongful conviction lawsuit against the city and went on to become a ruthless Chicago gang leader.

Jimenez has pleaded guilty to possessing a gun illegally in 2015. He and a sidekick, Jose Roman, were riding in Jimenez’s $90,000 Mercedes convertible when they pulled up to Earl Casteel on the Northwest Side, according to a sentencing memo filed Wednesday.

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Roman recorded the encounter, in which Casteel pleaded on the cellphone video, “you’re my brother, man. I ain’t got nothing against you.” Jimenez then shot Casteel in each leg. “Why would you do that?” Casteel asked. Jimenez replied, “Shut up, bitch” and drove off, the Chicago Sun-Times is reporting.

Chicago Police arrested the men and recovered a gun from each of them after a chase that ended with the Mercedes crashing.

Jimenez, 37, admitted he possessed the .380-caliber pistol he used to shoot Casteel. Roman pleaded guilty to the same charge for possession of a rifle the same day.

Prosecutors are seeking a 10-year sentence for Jimenez and a sentence of about seven years for Roman.

Jimenez was in prison for 16 years after he was convicted at 13 for the fatal shooting of a 19-year-old man in 1993 on the Northwest Side. He was freed in 2009 after his conviction was overturned.

He received $25 million in a lawsuit against the city and spent much of his fortune on his gang, the Simon City Royals, prosecutors said.

He recruited new members and paid them thousands of dollars each to tattoo the gang’s cross symbol on their faces, sources have told the Chicago Sun-Times.

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He bought a Range Rover for his friend Roman and put up $100,000 to help a fellow gang member post bail in a drive-by shooting that left a teenager paralyzed.

Jimenez’s stable of expensive cars included Bentleys and Lamborghinis, records show.

The North Side-based Simon City Royals — who previously kept a low profile among Chicago’s violent gangs — are suspected in multiple killings on the West Side, where they moved in on the drug trade in recent years, sources said.

Almost a dozen members of the gang have been charged with state and federal gun crimes since 2015.

In their filing Wednesday, prosecutors said Jimenez’s “nihilism and self-destructive behavior” could be explained by his tragic youth. But his past doesn’t excuse his decision to “glorify and perpetuate violence using funds intended to make him whole.”

He received a “sum that would be truly staggering to all but the wealthiest in this country. He could have used this money in any number of ways — to assist friends and family, contribute to the community, sponsor others wrongfully convicted or simply live in comfort for the rest of his natural life. Instead, he chose to build a gang,” prosecutors said.

In December, Jimenez suffered a major downturn in his fortunes when a Cook County judge awarded Casteel $6.3 million in a lawsuit he filed against Jimenez for shooting him. Last year, Jimenez said in court that he was practically broke.

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(Source: Sun-Times Media Wire © Chicago Sun-Times 2017. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)