Stockholm syndrome

«On August 23, 1973, Jan Erik “Janne” Olsson, on leave from prison, walked into Kreditbanken at Norrmalmstorg, central Stockholm and attempted to hold up the bank. Swedish police were called in immediately, two of them went inside, and Olsson opened fire, injuring one policeman. The other was ordered to sit in a chair and “sing something”. He started singing “Lonesome Cowboy”. Olsson then took 4 people as hostages. He demanded his friend Clark Olofsson to be brought there, along with 3 million Swedish Kronor ($730,000 US 1973 value), two guns, bullet-proof vests, helmets and a fast car.

Both Olsson and Olofsson were charged, convicted and sentenced to extended prison terms for the robbery. Olsson was sentenced to 10 years in prison. He received many admiring letters from women who found him attractive. He later married to one of his female admirers.

Olofsson later met hostage Kristin Ehnemark several times, their families becoming friends

— The Norrmalmstorg robbery at Wikipedia.