The undercover detective posing as a hired assassin sat across from his client in the Rikers Island visitation room last month and asked how he wanted the hit carried out.

In hushed tones, the inmate, David Brown Jr. — a 6-foot-3-inch, 375-pound man with a beard streaked with white — gave the order.
“I want his head chopped off,” he said.

The target: The police commissioner, Raymond Kelly.

The arrest of Brown, 47, was the culmination of an undercover investigation into a bizarre and disturbing plot that was disclosed to police last month. In an attempt to retaliate for the fatal shooting of Sean Bell last year, Brown was offering $65,000 to kill Mr. Kelly and blow up police headquarters at One Police Plaza.

It was unclear whether Brown had the means to pay someone to carry out his fantasy, but police yesterday charged him with criminal solicitation in the second degree, a felony. He is expected to be arraigned in the Bronx today. No lawyer or family member of Brown’s could be contacted as of press time.

Brown was back in jail after he violated his parole in June 2006 by disobeying an order of protection against his ex-wife. Before that, he had been serving a sentence for the attempted murder of the same woman, police officials said. He has been convicted of 14 felonies, including robbery, menacing with a weapon, and other violent crimes, police said.

Sometime after the Bell shooting last year, Brown apparently decided he wanted Mr. Kelly killed. He contacted a fellow inmate who he thought might be able to set him up with the right people to carry out the assassination, but the inmate instead told a third party outside of Riker’s Island to call the police about the plot, officials said.

That person waited for about a month before notifying the police through the Crime Stoppers hotline on February 13, police said. Detectives from the NYPD’s Intelligence Division took over the case.

On February 21, an undercover detective made a phone call to Brown in jail. Brown told the detective, whom he believed to be a professional hit man, that he was “fed up with the case where the guy got shot 50 times.”

Mr. Kelly didn’t have the “initiative to prosecute the officers,” he said, according to a transcript of the conversation. “That kind of got me frustrated to the point where I want him murdered.”

The two spoke three times, including once more on the phone on February 22, and then in person on February 23. Brown said he would pay $15,000 to have Mr. Kelly beheaded and another $50,000 for police headquarters to be blown up, police said. The detective advised him that blowing up a building could cost as much as $150,000. They agreed to talk again soon, police said.

“I want them to feel like I’m a … terrorist,” he said, according to the transcript of the third and final encounter.

Since entering police custody, Brown has “made statements” that he intended to have Mr. Kelly killed, a police spokesman, Deputy Commissioner Paul Browne, said.

This is not the first death threat that Mr. Kelly has received, but it is the first time someone has been charged with plotting against the commissioner, Mr. Browne said. He added that Mr. Kelly didn’t appear to be affected by the threat.

A spokesman for the Department of Correction, Stephen Morello, said Brown had mostly been staying at the North Infirmary Command on Riker’s Island and had spent a week at Bellevue Medical Center for an unknown ailment since he was incarcerated.

The plot was the first example of violence planned in response to the Bell shooting, though several groups have expressed outrage that police fired 50 bullets on the three unarmed men in the car. Trent Benefield and Joseph Guzman were injured in the shooting.

The grand jury in the Bell case heard yesterday from the police officer who fired one shot in the incident, Paul Headley. The remaining officers will testify this week, and a decision whether to indict any or all of the officers could come as early as next week.