WASHINGTON – A man on trial for murder and operating a massive drug ring in southeast D.C. has been threatening witnesses from his jail cell by using Facebook, prosecutors say.

Mark Pray, who is accused of running a drug gang in the Barry Farm housing project and the execution-style killing of a federal witness, has been using a cell phone that was smuggled into the D.C. jail to communicate with friends on Facebook and Twitter, the Washington Post reports.

Federal officials obtained a warrant to search Pray’s jail cell after they say he posted threats on the social media pages, the Post was first to report.

Prosecutors say Pray, using the Facebook name “Slick Ass Waldo,” wrote the name of a witness on his profile page, saying the witness was the first to “sell his soul.”

No cell phone was found when authorities searched Pray’s cell, and the Facebook page and Twitter account are now offline.

A law enforcement source says it’s not uncommon for prisoners to smuggle phones into the D.C. jail.

Pray’s trial began in January and is expected to conclude soon..

WTOP’s Mark Segraves contributed to this report. Follow WTOP on Twitter.

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