The federal government and all 50 states have enacted anti-stalking statutes, yet there is still no universally accepted definition of what constitutes stalking. When I talk about stalking, I’m referring to a pattern of behavior carried out by one person against another which is intended to harass, intimidate, or terrorize the victim—and usually does.  Cyberstalking occurred in about 25 percent of cases studied—which seems low to me. If my suspicion is correct, the reasons for the low numbers arise from the data collection methodology, the population being studied, and other reasons that I won’t digress on here. But it seems likely that cyberstalking is only likely to increase since the potential for surveillance and harassment is huge while the risk to the stalker is relatively small. RELATED: I Was Stalked By My Rapist — And Couldn’t Legally Stop Him Former spouses and paramours are the most common targets of stalking, followed by victims being stalked by an acquaintance. Only about one in four incidents involve stalking by a stranger. Most stalkers are men—70 to 80 percent, as reported by various studies—but one specific type of stalking is perpetrated almost exclusively by women.

The 7 Types of Stalkers

Dr. Ronald M. Holmes, professor emeritus of criminology, proposed these categories of stalkers:

1. Domestic

Stalking a former spouse or paramour. This is the most prevalent kind of stalking and one which can manifest in the workplace, putting innocent bystanders at risk.

2. Lust

Serial predators who stalk victim after victim. Serial rapists and murderers may begin as lust stalkers. For example, Ted Bundy.

3. Love-Scorned

An acquaintance, coworker, neighbor, etc. who desires an intimate relationship with the victim, but is rebuffed. (A sub-type of the love-scorned stalker is someone with the delusional disorder erotomania. This type of stalker—usually female—believes her target is madly in love with her. The woman who repeatedly broke into David Letterman’s home and stole his car, claiming to be his wife, is one example.)

4. Celebrity

Those who stalk famous people. For example, John Hinckley. RELATED: The Creepy Truth About Stalkers (And How To STOP Them)

5. Political: 

Stalking is motivated by political beliefs, which could include either agreement or disagreement with the victim. For example, Sirhan Sirhan.

6. Hit (murder for hire)

Stalking of a victim by a hired killer in order to commit murder.  I would propose adding one additional category to the list:

7. Revenge

An angry former employee, an aggrieved business partner, a resentful neighbor, a vindictive relative, or any other person—usually known to the victim—whose motive for stalking is payback. One example is the ex-con Max Cady in the movie, Cape Fear, who stalks Sam Bowden, the lawyer who represented him at trial. There is no reliable profile to predict who is likely to stalk. Some patterns have begun to emerge from research, and although these fall short of providing a reliable checklist, what we have learned so far is interesting and could be useful.  The following patterns apply to the U.S. population and may not apply to other nations:

Unemployed or under-employedLate 30s to late 40sHigh school and/or college graduateMore intelligent than most criminalsAny race or ethnicityMostly male (although erotomania is manifested overwhelmingly in females)Often delusional

In one study, clinical and personality disorders were present in more than half of the stalkers evaluated. (Generally, though, few stalkers are psychopathic, but some may be narcissistic, borderline, histrionic, or antisocial.) In another study, women reported being more afraid of being stalked by an unknown stranger than by someone they knew.  It’s easy to see why an unknown predator seems scarier: He or she is the boogeyman (or boogeyperson?)—mysterious, unapproachable, unpredictable, and capable of anything. Someone you know—even someone who holds a grudge against you—seems more finite and manageable. But the greater danger by far is the devil you know.  RELATED: 5 Signs He Isn’t Interested In You — He’s STALKING You Dale Hartley is associate professor and chair of the humanities, fine arts, and social sciences division at West Virginia University, Parkersburg.  For 23 years he was CEO of Lionhart Group, Ltd., an education management firm that delivered training programs at military bases in the U.S. and Puerto Rico. This article was originally published at Psychology Today. Reprinted with permission from the author.