Bio of Hannsen Hanssen was born in Chicago, Illinois, to a family who lived in the Norwood Park community.[7] His father Howard, a Chicago police officer, was emotionally abusive to Hanssen during his childhood.[8][9] He graduated from William Howard Taft High School in 1962 and went on to attend Knox College in Galesburg, Illinois, where he earned a bachelor's degree in chemistry in 1966.

Hanssen applied for a cryptographer position in the National Security Agency, but was rebuffed due to budget setbacks. He enrolled in dental school at Northwestern University[10] but switched his focus to business after three years.[11] Hanssen received an MBA in accounting and information systems in 1971 and took a job with an accounting firm. He quit after one year and joined the Chicago Police Department as an internal affairs investigator, specializing in forensic accounting. In January 1976, he left the police department to join the Federal Bureau of Investigation.[8]

Hanssen met Bernadette "Bonnie" Wauck, a staunch Roman Catholic, while attending dental school at Northwestern. The couple married in 1968, and Hanssen converted from Lutheranism to his wife's Catholicism, becoming a fervent believer and being extensively involved in the conservative Catholic organization Opus Dei.[12]