The Robert Durst gun charge is now a federal case.
The millionaire real estate heir and subject of HBO's "The Jinx" was indicted Friday for being a felon in possession of a firearm — a charge that carries up to 10 years in prison.
Durst was already being held in Louisiana on state charges of gun possession in connection with the .38-caliber Smith & Wesson that was seized by FBI agents who busted him on a murder charge out of California.
"Now it's not just the state of Louisiana against Robert Durst. It's the United States of America against Robert Durst," said Donald "Chick" Foret, a veteran New Orleans trial lawyer who has been closely following the case.
It's a federal crime for a convicted felon to have a firearm — and while Durst was acquitted of murder in 2003 for killing and dismembering an elderly Texas neighbor, he pleaded guilty to two gun charges the following year in exchange for a nine-month sentence.
The federal law is broader than Louisiana's statute, so prosecutors may have an easier time winning a conviction on the new charge.
Durst has argued the gun charge should be dismissed, saying it was seized illegally, before a search warrant was issued.
"It is rare in state court for a motion to suppress [evidence] to be granted," Foret said. "I have seen even fewer motions to suppress granted in federal court."
Legal experts also have said it may be easier for prosecutors to put Durst back behind bars on the gun rap than to prove he murdered his former confidant, Susan Berman, in Beverly Hills in 2000.
"There is no doubt state and federal prosecutors are working closely together," Foret said.
Durst has denied killing Berman. His arrest came days before the finale of the "The Jinx," which examined his links to the 1982 disappearance of his wife, Berman's death and the Texas slaying — and which ended with Durst apparently blurting out on a hot microphone that he had "killed them all."