Bulger chuckled in a California court Thursday as he appeared in public for the first time in 16 years.
"There's a lot of media here to see you," a marshal told Bulger, according to a federal official there. The shackled Bulger just laughed.
When the judge asked Bulger during the short hearing if he had read and understood the charges listed against him in a 200-plus page indictment, Bulger said he hadn't read it all but knew what was inside.
Bulger could face life in prison for the charges against him in Boston and possibly the death penalty for charges filed elsewhere, if he is convicted, Ortiz said. Greig could face up to five years in prison for harboring a fugitive.
Greig's twin sister, Margaret McCusker, told ABC News the arrest came as a shock.
"I am very emotional about all this but I have to say I am happy my sister is going to coming home," she said Thursday. "I talked to her the first couple of years but I haven't talked to her since. It's been a very long time. ... I didn't know if she was alive or dead, and suddenly it is within my grasp."
ABC News' Enjoli Francis, Jessica Hopper, Lee Ferran, Michael S. James and the Associated Press contributed to this report.