cluciano63, that's the conundrum; you can't rule them in, nor can you rule them out. This is common when stranger abductions occur. Seems with each unsolved abduction of another innocent victim, the occurance only escalates. Not because it is the same predators, but because it empowers others to act out their evil fantasies.
Ironically, the FBI redefined the definition of serial killer a few years ago & reduced the number of victims from 'three, to only two'.
Still scratching my head over this decision. This combined with the psychopathic behavior caused by many drugs has increased the number of serial killers astronomically, imo.
FBI Serial Murder
www.fbi.gov/stats-services/publications/serial-murder
To address these discrepancies, attendees at the Serial Murder Symposium examined the variations in order to develop a single definition for serial murder.