Previous studies have shown that prisoners are substantially more likely to kill themselves but little is known about increased risk among other people who have a brush with the law. Researchers from the University of Manchester and the University of Aarhus in Denmark studied 552,118 people in Denmark 27,219 of whom committed suicide. More than a third of all the men who killed themselves had a criminal-justice history although the relative risk was higher among women with a criminal-justice history. Suicide risk was markedly increased among people who had been in jail but the risk was even greater among people who had been sentenced to psychiatric treatment and who had had charges conditionally withdrawn. The risk of suicide was greater even in people who had not been sent to jail or who had been found innocent and was especially high in people who had had recent or frequent contact with the law or who had been charged with violent offences.
Webb, Roger T. ... [et al] - National study of suicide in all people with a criminal justice history Archives of General Psychiatry doi:10.1001/archgenpsychiatry.2011.7