1. fact
   fiction
2. almost fact: A serial killer has at least three victims.

The FBI defines a serial killer as one who murders three or more victims, with "cooling-off" periods between each murder.

1. fact
   fiction
2. almost fact: The number is more like 300.

According to a recent FBI study, there have been approximately 400 serial killers in the United States in the past century -- 80 percent of them have emerged since 1950.

1. fact
   fiction
2. almost fact: It's actually John Wayne Gacy.

H.H. Holmes is considered to be the United States' first serial killer. Holmes confessed to 27 murders in the 1890s and was convicted of nine. He began by killing guests at a hotel that he opened to host visitors to the 1893 World's Fair in Chicago.

1. fact
   fiction
2. almost fact: Eighty percent is the right number.

More than 80 percent of serial killers are male, Caucasian and in their 20s or 30s. They usually kill Caucasian women.

1. fact
   fiction
2. almost fact: It was actually Ted Bundy.

Precinct captain Gacy, a popular figure in his community, was convicted of killing 33 boys and men.

1. fact
   fiction
2. almost fact: It's the other way around.

Son of Sam was a thrill killer who enjoyed the excitement of the kill. Bundy got sexual satisfaction from his kills.

1. fact
   fiction
2. almost fact: It was Peter Woodcock.

Buffalo Bill shared serial killer Ed Gein's habit of making keepsakes from the body parts of his victims. Gein also inspired the character of Norman Bates in "Psycho" and Leatherface in "The Texas Chainsaw Massacre."

1. fact
   fiction
2. almost fact: It's "bind, torture, kill."

Rader bound, tortured and killed his victims and then bragged about it in letters to the police and local media.

1. fact
   fiction
2. almost fact: The MacDonald triad is bed-wetting, running away from home and doll torture.

The MacDonald triad is bed-wetting, arson and cruelty to animals. Serial killers are also likely to have come from broken homes and been abused or neglected.

1. fact
   fiction
2. almost fact: It's Aileen Wuornos.

Aileen Wuornos is in a sparsely populated category -- the female serial killer.