CBS Atlanta

Published: Nov 13, 2013 1:45 PM EST

MIAMI (AP) - A man who admits hijacking an airliner from the U.S. to Cuba almost two decades ago pleaded not guilty Wednesday to federal air piracy charges.
    
William Potts has said in interviews he decided to return from Cuba last week to face U.S. justice but nevertheless entered the not guilty plea at a brief hearing. He is seeking credit for the 13 years he spent in Cuban prison for the hijacking.
    
A bail hearing was postponed until next week after a 1984 arrest warrant surfaced charging Potts in a New Jersey armed robbery.
    
Potts' court-appointed attorney, Paul Korchin, said he had just learned about the outstanding warrant and needed time to investigate. It could affect whether Potts is granted bail as well as any potential prison sentence if he is convicted.
    
"We may have to do some background checking on this," Korchin said.
    
Federal prosecutors oppose releasing Potts on bail, saying he is a flight risk and a danger to the community.
    
No details about the New Jersey robbery were immediately available, other than that the arrest warrant remains active. It was issued in Bergen County, N.J., on Aug. 10, 1984, several months after the March 1984 hijacking.
    
Potts, 56, could get between 20 years and life in prison if convicted of the air piracy charges.
    
The FBI said Potts claimed to have explosives aboard the New York-to-Miami flight in 1984, demanding its diversion to Havana. Potts described himself then as a black militant who also used the names "Lt. Spartacus" and "William Freeman," and the FBI said he threatened to blow up the plane and kill passengers if it landed in Miami.
    
Although he hoped to be welcomed to Cuba and given guerrilla training, the Cubans instead arrested him and tried him for the hijacking. Potts' commandeering of the airliner came several years after a wave of similar hijackings had largely died down.
    
According to the FBI, Potts paid $119 for the ticket he used to hijack the Piedmont Airlines flight. An aunt in Paterson, N.J., said she had given him $120 the day before to pay her electric bill, and had not seen him since.
    
___
    
Follow Curt Anderson on Twitter: http://twitter.com/Miamicurt

(Copyright 2013 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)