Factors are classified as demographic, situational, clinical, and methodical. More than 50 percent of U.S. jail suicide victims were men, white, unmarried, under 28 years of age, charged with minor or drug-related offenses, and intoxicated with drugs or alcohol. Suicides significantly occurred in isolation. Suicide victims in the international study were significantly (p less than 0.001) men, white, married, pretrial, and charged with or convicted of violent offenses. Psychiatric diagnosis, alcohol abuse, taking psychotropic medication, and suicidal ideation were also positively correlated in the international study, but suicide victims were distributed more evenly over age-groups. Results of other studies illustrate the near universality of some findings. Three theories of suicide are briefly discussed. (Published Abstract)