Absconding by patients from acute psychiatric wards is known to be linked to self harm and harm to others. Previous research has focused only on officially reported absconds, thus missing out many patients who although they abscond and pose a risk, are never officially processed. This paper reports the findings of a large prospective study of absconding in the East End of London using an objective definition of absconding not linked to official bureaucratic processes. Absconders are considered by staff to be high risk patients, and many have histories of violence and/or suicide attempts. Nevertheless nurses only request the aid of the police in returning patients on 47% of occasions. The actions of the police are very variable, and range from two policemen calling at the patient's house, to an entire team in riot gear appearing at the patient's door in the early hours of the morning. Most absconds result in no harm to anyone, and most absconders return by themselves. Relatives and carers also play a significant role in persuading the patient to return or bringing them back. Nurses should develop more sophisticated ways of working with the police and with relatives to maintain absconding patients' safety.