Authorities found nearly 150g of marijuana and a revolver in the hotel room where they arrested Robert Durst, the millionaire who has long been suspected in three sensational murders.
Durst appeared before a judge for a second straight day to face the drug and weapons charges. He also is charged with murder in the killing in Los Angeles 15 years ago of a friend who acted as his spokeswoman.
He has also been suspected in the disappearance of his first wife and he won an acquittal on a murder charge in Texas.
Police said Durst's arrest on the murder charge was based on words he wrote, not the words he spoke at the end of an HBO documentary about his troubled life.
Analysis linking a letter Durst wrote to his friend Susan Berman a year before her killing with one he said "only the killer could have written" to point police to her body was the key new evidence in the long-dormant investigation into the 2000 killing, a spokesman said.
Durst, 71, was charged yesterday in Los Angeles with first-degree murder in the shooting of Ms Berman, the daughter of a prominent Las Vegas mobster. He could face the death penalty under special circumstances that allege he ambushed her and murdered a witness to a crime.
Authorities in New Orleans charged him late yesterday with being a felon in possession of a gun because he had a revolver when he was arrested on Saturday. Assistant district attorney Mark Burton said they found the pot and gun in his hotel room.
Lawyer Dick DeGuerin said he wants a hearing in Louisiana as soon as possible to contest the arrest.
"The warrant we believe is based on a television show and not on actual fact," he said. "We want a hearing as quickly as possible so Mr Durst can go to California and face trial as quickly as possible."
The judge in New Orleans, Harry Cantrell, scheduled another hearing for next Monday.
Presented with the two letters in the finale of The Jinx: The Life And Deaths Of Robert Durst, which aired on Sunday on HBO, the eccentric heir blinked, burped oddly, pulled his ear and briefly put his head in his hands before denying he was the killer.
Then he stepped away from the tense interview and went to the bathroom, still wearing a live microphone which recorded what he said next.
"There it is. You're caught!" Durst whispered before the sound of running water is heard. "What the hell did I do? Killed them all, of course."
That moment did not just make for a captivating ending to the documentary on the eccentric life of an heir to a New York property fortune, it could also provide additional evidence for prosecutors.
Officials said the bathroom recording was not presented to prosecutors before charges were filed because detectives were still trying to determine if the recording was tampered with.
But legal experts said the audio and other parts of the interview could become key evidence.