Associates of Mark Rossetti are calling for the dismissal of key evidence in the criminal case against them, accusing State Police of a delay in telling a judge involved that the reputed mobster was working for the government and that an FBI supervisor lied to state investigators about his use.
The FBI’s alleged denial of its relationship with Rossetti contradicts previous claims from the agency and State Police that the two agencies had cooperated during the investigation into Rossetti’s alleged crime ring. The information was revealed in a court motion filed last week by Robert A. George, who is representing two men accused of participating in the ring.
The court documents contend the State Police later learned Rossetti was probably working with the FBI and misled a Superior Court judge, John T. Lu, by withholding the information when seeking the court’s permission for wiretaps.
The wiretaps were approved in January 2010, a few months before Rossetti was arrested on charges of trafficking heroin. Investigators intercepted 44 phone calls between Rossetti and his FBI handler between January and when he was arrested in May.
“It is undisputed that the State Police knew that the federal informant was their prey before Jan. 7, 2010, yet not only kept his status but also his investigative importance from Judge Lu until after he had been intercepted on their wiretap,’’ according to the motion.
The disclosures, which cite a sealed affidavit filed by prosecutors in 2010, raise new questions about the FBI’s relationship with Rossetti, and whether the agency’s apparent secrecy may compromise a pivotal investigation.
Rossetti is accused of running a vast and violent criminal enterprise that engaged in gambling, loan sharking, and drug dealing. He is suspected in at least six homicides, law enforcement officials say.
In filing the motion, George contends that investigators obtained the wiretap that led to the arrests of Joseph Giallanella and Michael Petrillo through misleading pretenses, and argues the evidence should be suppressed. The men are alleged to have been involved in the crime ring.
“It is ironclad law that the Fourth Amendment forbids the government to make false or misleading representations to the court, in order to protect the confidentiality of its informants,’’ the motion stated.
Spokesmen for the FBI and the State Police declined to comment because the case is before the courts.
A spokesman for the state’s attorney general could not be reached for comment.
In the motion, George cites the sealed affidavit that alleges that in December 2008 or January 2009, a FBI supervisor denied to State Police that Rossetti was an informant.
State Police said they may be targeting Rossetti, and the supervisor did not react “in any appreciable way.’’
In August 2009, Rossetti told a State Police sergeant he had talked with the FBI in the past, and that the FBI had previously “done a favor for him.’’
This August, the Globe reported that Rossetti was an FBI informant, citing court documents. In response, the FBI and State Police released a statement saying the FBI learned of Rossetti’s alleged criminal activity from State Police, and was prepared to cut ties with him. But State Police urged the FBI to maintain the association for “logical strategic reasons.’’
“The FBI cooperated for months with the Massachusetts State Police, assisting their organized crime unit until the investigation was complete,’’ the statement said.
The statement did not describe how long Rossetti worked with the FBI, or whether he provided useful information.
In the motion, George writes that since the “cat is out of the bag’’ in terms of Rossetti’s relationship with the FBI, the court should focus on why state investigators did not disclose him as an informant.
In previously filed court documents, Rossetti said he believed he would be protected by the FBI after he realized he was being targeted by State Police.
According to taped conversations contained in the court documents, Rossetti’s FBI handler told him not to worry, that “my job is to keep you anonymous and keep you safe.’’
“You don’t have anything to worry about if things down the road happen, but if that happens, we’ll have to deal with it as it comes,’’ the handler told Rossetti. “I will have to start working it out.’’
George has filed several motions to learn more about Rossetti’s relationship with the FBI, including several affidavits that were filed under seal with the court.
The affidavit cited by George was made available because of his repeated requests for the documents.
Lawyers for other codefendants in the case have submitted similar requests, arguing that Rossetti’s involvement with the FBI, and state investigators’ awareness of it, undermine the charges against their clients.
Under established law, a defendant cannot be charged with conspiring with a ring leader if that ring leader was working on behalf of the government.
State prosecutors who oppose the requests for information argue that Rossetti’s relationship with the federal government had no influence on their case.Peter Schworm can be reached at firstname.lastname@example.org. Follow him on Twitter @globepete. Milton Valencia can be reached at email@example.com.