Four men caught in an elaborate FBI sting plotting to blow up New York City synagogues and shoot down military planes were "ticking time bombs" who needed to be taken off the streets and put behind bars for life, federal prosecutors said Wednesday in court papers.

James Cromitie, David Williams, Onta Williams and Laguerre Payen were found guilty last year of conspiracy to use weapons of mass destruction and other charges. Their lawyers have argued they deserve a break because they were under the spell of a paid FBI informant posing as an Islamic extremist and promising a big payday, and that they never posed an actual threat.

In a memo filed in anticipation of the sentencing of three of the men next week in federal court in Manhattan, prosecutors countered that it doesn't matter that they never had access to real weapons and were under close watch the whole time.

"Few people in the world would agree to do such horrible things," the government wrote in asking a judge to impose life sentences. "Not for money. Not for anything. ... From the FBI's perspective, leaving people susceptible to such recruitment on the streets, like ticking time bombs, is unimaginable no matter how long the odds."

The men's trial featured 13 days of testimony by undercover informant Shahed Hussain, a Pakistani immigrant that the FBI assigned in 2008 to infiltrate a mosque in Newburgh, about an hour north of New York. After meeting Cromitie at the mosque, Hussain told him he was a representative of a Pakistani terror organization that was eager to finance a holy war on U.S. soil.

Prosecutors told jurors that in meetings with Hussain, Cromitie hatched the scheme to blow up the synagogues in the Bronx with remote-controlled bombs and shoot down cargo planes at the Air National Guard base in Newburgh with heat-seeking missiles. They said he also recruited the other men to be lookouts with promises of money. Onta and David Williams are not related.

Agents arrested the men in 2009 after they planted the devices — fakes supplied by the FBI — in the Riverdale section of the Bronx while under heavy surveillance.

In one of several videos played at trial, the men were seen inspecting a shoulder missile launcher in a bugged warehouse in Connecticut two weeks before the planned attack. At the end of the tape, Cromitie, two of his cohorts and the informant bow their heads in prayer.

Jurors also heard tapes of Cromitie ranting against Jews and U.S. military aggression in the Middle East

"I'm ready to do this damn thing," Cromitie said on one tape. "Anything for the cause."

Defense attorney have argued the FBI overreached by targeting desperate, down-and-out dupes who were only in it for the petty cash and meals the informant gave them. Cromitie, they said, constantly wavered and even purposely disappeared for six weeks before finally agreeing to go forward with the plan.

But prosecutors said Wednesday in the end, Cromitie "showed up again with renewed vigor" to carry out the plot.

"The highly publicized case stands as a deterrent to others similarly willing to accept the advances of a smooth-talking outsider bent on bringing harms to the nation," prosecutors wrote.

Payen's sentencing has been put off pending the results of a psychiatric evaluation.