Hansen was born in Estherville, Iowa to Edna and Christian Hansen, who was a Danish immigrant. In 1960, he burned down a bus garage. He was convicted of arson and sent to prison. His wife divorced him when he was in prison. He was assessed as having an infantile personality and released in 1962. He married another woman in 1963. The couple and their two children moved to Anchorage, Alaska, in 1967. In 1977, he was convicted of theft and sent to prison. He was diagnosed with bipolar disorder and in 1978 was released. In 1983, he was charged with assault, kidnapping, firearms offences, theft and deception.
Between 1971 and 1983, Hansen abducted, raped, tortured and murdered at least 17 and possibly as many as 21 women in and around Anchorage. He was discovered, arrested, and convicted of four murders in 1984. He was sentenced to 461 years plus a life sentence with no possibility of parole.
- "Hunting humans". Archived from the original on 2014-08-26. Retrieved 2014-08-21.
- 'Butcher Baker' Robert Hansen moved to Anchorage for medical treatment Archived 2014-06-27 at the Wayback Machine, Alaska Dispatch.
- "Frozen ground serial killer Hansen dead". Alaska Dispatch. March 19, 2014.[permanent dead link]