Within months, Boyce was promoted to a highly sensitive position in TRW's "Black Vault" (classified communications center) with a top secret security clearance, where he worked with National Reconnaissance Office (NRO) transmissions.

[3] Boyce said that he began getting misrouted cables from the CIA discussing the agency's desire to depose the government of Prime Minister Gough Whitlam in Australia.

[citation needed] Instead, he gathered a quantity of classified documents concerning secure US communications ciphers and spy satellite development and had his friend Andrew Daulton Lee, a cocaine and heroin dealer since his high school days (hence his nickname, "The Snowman"), deliver them to Soviet embassy officials in Mexico City, returning with large sums of cash for Boyce (nicknamed "The Falcon" because of his longtime interest in falconry) and himself.

He was convicted on eight counts of espionage on April 28 1977, and sentenced by federal district judge Robert Kelleher on September 12 to forty years in prison, initially at Terminal Island, then the Metropolitan Correctional Center in San Diego.

[13] While a fugitive, Boyce carried out 17 bank robberies in Idaho and Washington, hoping to pay for passage to the Soviet Union, and adopted the alias of "Anthony Edward Lester".

On January 26, 1982, in Los Angeles, Boyce was convicted of escape from federal prison in a nonjury trial before U.S. District Court Judge Lawrence Lydick, a proceeding which lasted three minutes.

[32] In April 1985, Boyce gave testimony on how to prevent insider spy threats to the Senate Permanent Subcommittee on Investigations as part of its Government Personnel Security Program.

Karr had planned to blind Boyce with a mace-like concoction after luring him into his cell, then electrocute him using a homemade electric shock prod fashioned out of a rod and newspaper.

[41] In 2013, Boyce published a book titled American Sons: The Untold Story of the Falcon and the Snowman, which mainly discusses his time in prison and relationship with his wife, Kathleen, and writer Vince Font.

[41] When interviewed at the time his book was released, Boyce expressed support for the actions of Edward Snowden in exposing information about the United States government's surveillance programs.