The police went along with Olsson's demands and arranged for Olafsson to be brought to the bank and a communication link to be established with the police negotiators. Over the course of the next five days, Olsson and Olafsson continued to hold the hostages and threatened to kill them if their demands went unmet.
Finding the police negotiators to be too unreasonable, the hostage-takers even telephoned then-Prime Minister, Olaf Palme, and attempted to make their demands to him directly. After Palme refused their demands, he received a second call from hostage, Kristin Enmark, who expressed annoyance over his refusal to allow the robbers to leave with their hostages. The two robbers finally surrendered on August 28 after a gas attack on the bank itself. None of the hostages had been injured despite numerous threats of death. Both Olsson and Olafsson were charged and convicted although Olafsson claimed to have simply gone along with Olsson to keep the hostages safe (his conviction was later overturned on appeal). Kristin Enmark maintained contact with Clark Olafsson during his trial and assisted in his defence. She also remained friends with him after his release.
During the hostage crisis, criminologist and psychiatrist, Nils Bejerot served as an advisor to the police negotiators and interviewed the hostages after their release. He noted that the hostages reported considerable sympathy for their captors and stated that they had been mainly frightened over what the police might do to rescue them. It was Bejerot who first coined the term "Stockholm syndrome" and used it in a media interview. Although its actual clinical validity was suspect, the term took on a life of its own and entered the popular culture.
Also known as hostage identification syndrome (HIS), Stockholm Syndrome is apparently characterized by an emotional bond that forms between hostages and their captors which can manifest either unidirectionally (hostage towards captor only) or reciprocally (mutual emotional bond between hostage and captor). The formation of an emotional bond has even been observed going on the other direction with captors developing sympathy for hostages (also known as Lima Syndrome) although its occurrence is considerably rarer.
The existence of Stockholm Syndrome is often taken for granted by authority figures and hostage negotiators despite the lack of consistent evidence noted in released hostages. The Stockholm Sydrome has also been advanced to explain the formation of loyalty bonds in cases of domestic and child abuse (also known as identification with the aggressor) as well as in prisoners of war and concentration camp survivors. It should be noted that the lack of clear correspondence between hostage situations to more long-term abusive relationships limits possible generalization. Famous cases (such as the Patty Hearst kidnapping) have lent a certain legitimacy to the existence of Stockholm Syndrome but actual research using simulated hostage situations and hostage debriefings tend not to be so straightforward.
In a classic 1985 paper by James T. Turner of the University of Tennessee, he identified specific factors believed to play a role in the formation of HIS. These factors include: face-to-face contact between hostage and captor, a common language (he described a 1977 incident in which only those hostages who spoke the same language as their captors developed HIS), pre-existing beliefs regarding the moral justification of the hostage-taker's goals, absence of unwarranted violence (deliberate mistreatment of hostages), and development of identification with the captor. The final factor that Turner identified was length of captivity with likelihood of positive interactions forming between hostages and captors increasing over time.
It was largely with the expectation of Stockholm Syndrome that hostage preparedness training programs have been developed to teach diplomatic and military personnel who are deemed to be at high risk of capture to cope effectively. Despite the events of September 11, 2001, use of hostage preparedness training still focuses on awareness of potential emotional problems both during the hostage crisis and in coping with the aftermath. Unfortunately, studies examining the validity of such training in actual hostages remains rare.
As for Jan Erik Olsson, the bank robber who had started it all? While serving his sentence, he received numerous letters from female admirers and later married one of them (contrary to popular belief, she was not one of the hostages). He returned to a life of crime after his release. In 2006, Olsson attempted to turn himself over to Swedish authorities believing that he was still a fugitive for crimes that he had committed. The police informed him that the charges had been dismissed and he was sent on his way. His current whereabouts are unknown (but his legacy remains).