*WASHINGTON : *The U.S. government has identified a suspect in the leaklast year of a large portion of the CIA’s computer hacking arsenal, thecyber-tools the agency had used to conduct espionage operations overseas,according to interviews and public documents.

But despite months of investigation, prosecutors have been unable to bringcharges against the man, who is a former CIA employee being held in aManhattan jail on unrelated charges.

Joshua Adam Schulte, who worked for a CIA group that designs computer codeto spy on foreign adversaries, is believed to have provided the agency’stop-secret information to WikiLeaks, federal prosecutors acknowledged in ahearing in January. The anti-secrecy group published the code under thelabel “Vault 7″ in March 2017.

It was one of the most significant leaks in the CIA’s history, exposingsecret cyberweapons and spying techniques that might be used against theUnited States, according to current and former intelligence officials. Someargued that the Vault 7 disclosures could cause more damage to Americanintelligence efforts than those by former National Security Agencycontractor Edward Snowden. He revealed extraordinary details about thecapabilities of the United States to spy on computers and phones around theworld, but the Vault 7 leaks showed how such spying is actually done, thecurrent and former officials argued.

Schulte’s connection to the leak investigation has not been previouslyreported.

Federal authorities searched Schulte’s apartment in New York last year andobtained personal computer equipment, notebooks and handwritten notes,according to a copy of the search warrant reviewed by The Washington Post.But that failed to provide the evidence that prosecutors needed to indictSchulte with illegally giving the information to WikiLeaks.

A government prosecutor disagreed with what he called the”characterization” by Schulte’s attorney that “those search warrantshaven’t yielded anything that is consistent with [Schulte’s] involvement inthat disclosure.” But the prosecutor, Matthew Laroche, an assistant U.S.attorney in the Southern District of New York, said that the government hasnot brought an indictment, that the investigation “is ongoing” and thatSchulte “remains a target of that investigation,” according to a courttranscript of the Jan. 8 hearing that escaped public notice at the time.

Part of that investigation, Laroche said, was analyzing whether atechnology known as Tor, which allows internet users to hide theirlocation, “was used in transmitting classified information.”

In other hearings in Schulte’s case, prosecutors have alleged that he usedTor at his New York apartment, but they have provided no evidence that hedid so to disclose classified information. Schulte’s attorneys have saidthat Tor is used for all kinds of communications and have maintained thathe played no role in the Vault 7 leaks.

Schulte is in a Manhattan jail on charges of possessing, receiving andtransporting child pornography, according to an indictment filed inSeptember. He has pleaded not guilty.

A former federal prosecutor who is not connected to the case said that itis not unusual to hold a suspect in one crime on unrelated charges and thatthe months Schulte has spent in jail do not necessarily mean thegovernment’s case has hit a wall. The former prosecutor, who spoke on thecondition of anonymity to discuss an open investigation, also said that ifgovernment lawyers acknowledged in a public hearing that Schulte was atarget, they probably suspect he acted alone.

In documents, prosecutors allege that they found a large cache of childpornography on a server that was maintained by Schulte. But he has arguedthat anywhere from 50 to 100 people had access to that server, whichSchulte, now 29, designed several years ago to share movies and otherdigital files.

Schulte worked in the CIA’s Engineering Development Group, which producedthe computer code, according to people with knowledge of his employmenthistory as well as the group’s role in developing cyberweapons.

At the time of the leak, people who had worked with that group said thatsuspicion had mainly focused on contractors, not full-time CIA employeessuch as Schulte. It is not clear whether the government is pursuingcontractors as part of the leak investigation, but prosecutors have notmentioned anyone other than Schulte in court proceedings.

Schulte, who also worked for the NSA before joining the CIA, left theintelligence community in 2016 and took a job in the private sector,according to a lengthy statement he wrote that was reviewed by The Post.

The CIA declined to comment.