The man who has confessed to being Philadelphia's "Kensington Strangler" claims he didn't mean for the women to die, but experts on what they call sexual, serial killers believe the suspect knew what he was doing and "enjoyed the act of killing them."
Sources told ABC Affiliate WPVI that Antonio Rodriguez has confessed to police that he murdered Elaine Goldberg, Nicole Piacentini and Casey Mahoney between November and mid-December of last year. Prosecutors have approved charges to be filed against Rodriguez today. He is expected to be formally charged with three counts each of murder, rape, involuntary deviate sexual intercourse and abuse of a corpse.
Rodriguez is also a suspect in the sexual assault of at least three other women.
The 22-year-old suspect is described as soft spoken and at 5-feet-9 and 150 pounds is slightly built.
Police sources told the Philadelphia Inquirer that during his interrogation, Rodriguez said that he didn't set out to kill the women and that he knew he had to stop.
Rodriguez wanted to have "rough fantasy sex," choking the women until they were unconscious, but he did not want to kill them, sources told the Inquirer.
Forensic psychologists told ABC News that Rodriguez, if convicted of being the Kensington Strangler, fits the profile of a sexual, serial killer.
Forensic psychologist Louis B. Schlesinger said that sexual, serial killers often choose strangulation as the method of their murder because it's up close and personal.
"Strangulation allows an individual to control the speed at which the victim dies and this is very sexually stimulating for him," Schlesinger said. "It's not uncommon to strangle until almost the point of death, then release the pressure as she [the victim] is about to die so so he can increase the time of the sexual strangulation."
Dr. James Alan Fox of Northeastern University who has written five books about serial killers, said sexual serial killers are uniquely sadistic murderers and Rodriguez's claim that he didn't mean to kill the women is not convincing.
"He certainly knew that choking could lead to death... It may not mean that having them dead was his purpose…but he certainly enjoyed the act of killing them and overpowering them through strangulation," Fox said.
Most serial killers who fit the pattern of behavior for the Kensington Strangler are between the ages of 25 and 35, Schlesinger said.
"He didn't wake up one day...this began 10, 15 years ago in his mind, in his fantasies and so eventually he then acted out," Schlesinger said.
Some serial, sexual killers like Gary Ridgway, dubbed the Green River Killer, are able to elude authorities for dozens of years.
Ridgway was arrested in 2001 in Washington state for killing dozens of women by strangling them. Four of his victims were found in the Green River.
"Some individuals can plan crimes and elude law enforcement for a significant period of time...others act out in an impulsive way. The crime is unplanned, there's a lot of evidence left behind and they typically get apprehended more quickly," Schlesinger said.
The Kensington Strangler left behind DNA evidence that eventually led to his arrest. DNA results from a previous conviction on drug charges pointed to Rodriguez. Fresh DNA results taken after his arrest also linked him to the murders.