The Los Angeles Police Department did a study of 102 cases, enabling them to classify people who stalk. The LAPD study indicates that most stalkers are male (80%); among females, same-sex partners were the most likely to be physically dangerous stalkers; and 80% of stalkers never carry out their threats.
Sixty percent of the cases studied were described as simple obsessional cases. These were offenders who knew their victims. They were usually former spouses, lovers, or employers. The stalker had an emotional attachment to the victim. Eighty percent were male offenders in the age range of 30-40. Typically these types of stalkers begin stalking as a result of marital separation or perceived mistreatment by an intimate. Approximately 97% made prior threats and 30% carried out those threats.
Those classified as love obsessional were strangers to their victims. These cases represented 30% of the cases, and almost all (97%) were male offenders. The age range 30-40 when each began a campaign of harassment to make the victim aware of his presence. About 25% of these offenders made prior threats, but only three percent (one out of 31) carried them out. Unlike other categories, victims of love obsessional stalkers tended to be younger than the offender (ages 20-30).
Erotomania is a relatively rare, typically female phenomenon. Cases of erotomania involve offenders who believe that a public figure is in love with them. Cases of erotomania represent only eight percent of all cases in this study. Approximately 85% of the offenders are female, usually age 30-40. Prior threats were made in 40% of the cases. However, most of these offenders are letter writers (12%) who seldom confront the victim.
False Victimization Syndrome:
The final classification identified by the Threat Management Unit is the rarest (two percent of all cases) among stalkers. These are persons with a conscious or subconscious desire to be placed in the victim's role. By insisting that someone is stalking him or her, the offender becomes the victim. There appears to be some similarity between this classification and Munchausen Syndrome by Proxy, in which the offender harms the victim, then seeks medical assistance for the victim (usually the child of the female offender) in order to draw attention to herself or himself.