By Bernard Vaughan

NEW YORK, Jan 31 (Reuters) - Jailhouse posts on Facebook were at the center of a federal judge's examination on Thursday of how much information prosecutors must provide to defendants about cooperating witnesses.

Judge William Pauley of U.S. District Court in Manhattan issued an order that prosecutors were not obligated to provide a defendant with access to a cooperating witness's Facebook posts because they never possessed the account.

This isn't the first ruling the judge has made about Facebook posts in the case. Pauley issued a finding last year that prosecutors could access the defendant's Facebook profile from an informant who was one of his friends on the social networking site.

The case involves a Bronx man, Melvin Colon, who was indicted along with other members of the "Courtlandt Avenue Crew" on narcotics and racketeering charges. A member of the gang, Devin Parsons, agreed in August 2011 to cooperate with the government, Pauley wrote in the order. Colon has pleaded not guilty.

While incarcerated, Parsons used a mobile phone to post messages on a Facebook account that he had asked a friend to create for him under an alias, according to Pauley's order. Under his alias, Parsons reflected on life in jail and his cooperation, Pauley wrote.

"be home sooner then yall hereing lol(.)," he wrote in one post.

When his posts were revealed, the government tried to get access to the Facebook account but Parsons had already ordered his friend to delete it, Pauley wrote. Facebook told the government that it could not access the account without permission from Parsons's friend, the judge said.

Colon moved to compel the government to direct Parsons' friend to provide the log-in information for the deleted Facebook account, arguing his due process rights were violated because Parsons was a member of the prosecution team.

'GOVERNMENT AGENT'

Pauley denied that motion on Oct. 15. In his Thursday order explaining that decision, the judge said his ruling rested in large part on his contention that Parsons and other cooperating witnesses are often not, in fact, members of the prosecution team.

Cooperating witnesses, he wrote, have not served the law but violated it.

"They are not concerned with the escape of guilt or the suffering of innocents," he wrote. "Their cause is their own."

Pauley pointed to precedent established by the 2nd U.S. Circuit Court of Appeals that "an informant becomes a government agent ... only when the informant has been instructed by the police to get information."

"The Government never instructed Parsons to make the Facebook posts and instead asked Parsons to surrender all the information he had," Pauley wrote. "Because the prosecutors provided Colon with the information that was in their possession, the Government discharged its obligations" under the due process clause of the Fifth Amendment.

Pauley also disagreed with Colon's argument that the government had a duty to get access to the Facebook account, noting a 7th U.S. Circuit Court of Appeals opinion in 2002 that said due process rights do "not require the government to act as a private investigator and valet for the defendant."

In his ruling last August on Colon's Facebook posts, Pauley found that Colon's legitimate expectation of privacy ended when he disseminated posts to his Facebook friends because they were free to use that information however they wanted.

"When Colon posted to his Facebook profile and then shared those posts with his 'friends,' he did so at his peril," the judge wrote.

Attorneys for Colon and the government did not immediately respond to requests for comment.

The case is United States of America v. Joshua Meregildo, U.S. District Court in Manhattan, No. 1:11-cr-00576-WHP.

For Colon: Anthony Cecutti of Romano & Kuan.

For the United States: Santosh Shankaran Aravind of the U.S. Attorney's Office for the Southern District of New York.

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