A 31-year-old Baltimore drug dealer, who murdered an FBI informant in south Baltimore's Westport neighborhood in 2009, was sentenced Wednesday to four life terms in federal prison, the Maryland U.S. Attorney's Office announced.

Antonio "Mack" Hall was convicted in August of killing Kareem Kelly Guest, who told investigators that Hall liked to "bang the gun" and was connected to several drug-related Baltimore killings. Jurors also found Hall guilty of weapons violations and a seven-year conspiracy to distribute crack cocaine.

"This tragic case demonstrates what can happen when information about witnesses in criminal cases is not protected," U.S. Attorney Rod J. Rosenstein said in a statement.

A criminal defense attorney leaked information showing that Guest was cooperating with federal investigators. A copy of the document was distributed throughout Westport.

Prosecutors turned Halls' friends into informants during his trial, bringing a girlfriend and a fellow drug dealer into court to testify against him.

tricia.bishop@baltsun.com

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