Investigators at the time named him the “most wanted” computer hacker in the world.

In 1995, after a more than two-year-long manhunt, Mr. Mitnick was captured by the F.B.I. and charged with the illegal use of a telephone access device and computer fraud. “He allegedly had access to corporate trade secrets worth millions of dollars. He was a very big threat,” Kent Walker, a former assistant U.S. attorney in San Francisco, said at the time.

In 1998, while Mr. Mitnick awaited sentencing, a group of supporters commandeered The New York Times website for several hours, forcing it to shut down.

The next year, Mr. Mitnick pleaded guilty to computer and wire fraud as part of an agreement with prosecutors and was sentenced to 46 months in prison. He was also prohibited from using a computer or cellphone without the permission of his probation officer for the three years following his release.

Mr. Mitnick grew up in Los Angeles as an only child of divorced parents. He moved frequently and was something of a loner, studying magic tricks, according to his 2011 memoir, “Ghost in the Wires.”

By the age of 12, Mr. Mitnick had figured out how to freely ride the bus using a $15 punch card and blank tickets fished from a dumpster, and in high school he developed an obsession with the inner workings of the switches and circuits of telephone companies.