(Bloomberg) -- When accused child sex trafficker Jeffrey Epstein filed a bail request this week, he provided a glimpse of the strategies he is likely to use in his defense.Epstein was arrested last Saturday on federal charges of conspiracy and sex trafficking in minors and has pleaded not guilty. The 66-year-old fund manager and globe-trotting socialite, accused of molesting girls as young as 14 from 2002 to 2005, could spend the rest of his life in prison if convicted.On Thursday, in a letter to U.S. District Judge Richard Berman in Manhattan, his lawyers asked that he be released from jail while he awaits trial.“Mr. Epstein has substantial grounds to challenge the allegations charged by the government in its indictment, and he has every intention of doing so in a lawful, professional, and principled manner,” they told Berman in the filing.Here are some of the defenses they cited.Done DealEpstein claims he is immune from the charges as a result of a non-prosecution agreement he signed with federal prosecutors in Florida in 2007. An FBI investigation at the time turned up dozens of victims. He pleaded guilty in June 2008 to two state charges of soliciting prostitution and spent 13 months in prison, where he was allowed out six days a week to continue his work in fund management. The agreement “promised him immunity and a global settlement for offenses” including sex trafficking, his lawyers argue.“This is basically the Feds today, not happy with what happened in the decision that led to the NPA, redoing the same conduct that was investigated 10 years ago and calling it, instead of prostitution, calling it sex trafficking,” Reid Weingarten told U.S. Magistrate Judge Henry Pitman at a hearing Monday. “We think that is the heart of everything, and that will be the centerpiece of our defense, at least legally.”Defense lawyers also say the non-prosecution deal was not limited to a “list of several dozen victims identified in the prior investigation.” Instead, they say, the accord immunized Epstein from prosecutions “for the offenses” outlined in the agreement, as well as “any offenses that arose from the federal grand jury investigation.”And the defense intends to show that top Justice Department officials signed off on the Florida deal. They even “helped negotiate the resolution of the matter,” the lawyers say.What Trafficking?Whatever he may have done with the girls, it doesn’t fall under the federal sex-trafficking law he’s charged with breaking, Epstein’s lawyers contend.“There are no allegations in the indictment that Mr. Epstein trafficked anybody for commercial profit; that he forced, coerced, defrauded, or enslaved anybody; or that he engaged in any of the other paradigmatic sex trafficking activity” the federal law targets, according to the filing.“Importantly,” the defense notes, citing case law, “the entire language and design of the statute as a whole indicates that it is meant to punish those who are the providers or pimps of children, not the purchasers or the johns.”Due ProcessEpstein claims the Justice Department violated his constitutional right to due process by pursuing the New York case after he had already pleaded guilty and served his sentence in Florida in compliance with the non-prosecution agreement the U.S. had signed.What’s more, the defense suggests that the prosecution is improperly relying on physical evidence seized during the Florida investigation.There are “significant due process issues about the Department of Justice’s conduct in this case,” defense lawyers wrote.Too LateWhile there’s no statute of limitations involved in the charges against him, Epstein claims the government waited too long in bringing them, knowing the evidence against him for more than a decade.“Delays of 14 years from the last alleged act and 12 years since Mr. Epstein signed the NPA are extraordinary,” defense lawyers say, referring to the non-prosecution agreement. “The government will have to explain why it purposely delayed a prosecution of someone like Mr. Epstein.”Read MoreLabor Chief Acosta to Quit After Furor Over Epstein Sex InquiryEpstein Lawyer Dershowitz Defends Work, Fights Defamation CaseMystery Around Jeffrey Epstein’s Fortune and How He Made ItEpstein Accuser Seeks to Question Him Before Filing LawsuitThe FactsThese defenses target the legal, rather than factual, underpinnings of the case. They’d be matters for the judge to rule on before trial, based on legal briefs, rather than for a jury to decide. They would likely be deployed to persuade Berman to limit or even throw out the charges.The letter hinted at some factual defenses, too.“Yes, the government may have witnesses who will testify to participating in sexual massages – most over 18; some under; some who told the police they lied about their age to gain admission to Mr. Epstein’s residence; some who will testify that Mr. Epstein knew they were not yet 18,” Epstein’s lawyers wrote to the judge.They say the evidence shows Epstein’s alleged crimes were local sex offenses, not interstate trafficking.Prosecutors have until 5 p.m. Friday in New York to file arguments against granting Epstein bail. Berman will hold a bail hearing on Monday.The case is U.S. v. Epstein, 19-cr-00490, U.S. District Court, Southern District of New York (Manhattan).Read MoreEpstein Joins ‘El Chapo’ in Notorious Jail as Inmate 76318-054Barr Won’t Recuse Himself From New Case Against Jeffrey EpsteinTo contact the reporter on this story: Bob Van Voris in federal court in Manhattan at rvanvoris@bloomberg.netTo contact the editors responsible for this story: David Glovin at dglovin@bloomberg.net, Peter JeffreyFor more articles like this, please visit us at bloomberg.com©2019 Bloomberg L.P.