PHILADELPHIA (CBS) — Did the Kensington strangler strike again? Police are looking into yet another case involving a woman who claims she was choked and sexually assaulted overnight.

“I would advise all women to take precautions,” William Fleisher said. He added, “80 percent of our polygraph work are sexual offenders and there are different types.”

Fleisher, of Keystone Intelligence Network, is now retired and runs his own investigation and polygraph firm. He is not involved with the Kensington investigation but has handled similar cases in the past as a Philadelphia police officer and FBI special agent for almost 30 years.

Fleisher said, “There’s nothing sexual about it for any of these people. It’s like a psychological imperative.”

Fleisher calls the suspect in the Kensington cases, a “power assertive” criminal.

“A power assertive person literally derives pleasure of choking the life out of people,” Fleisher explained.

Police have linked the strangulation deaths of two women. Elaine Goldberg was just 21-years-old. Nicole Piacentini, 35. Both were found half naked in empty lots in Kensington after police say they were sexually assaulted and strangled. According to police, DNA links one man to both murders, but little else is known about their killer.

Police say he may also be responsible for two sexual assaults and two attempted assaults.

Overnight Tuesday, a seventh victim reported she got into a pick up truck in Frankford with a man who choked and then sexually assaulted her. Police say they are looking to see if the latest attack is connected to the others.

According to Fleisher, women in the area should be on alert, walk in pairs and avoid dangerous areas. He says whoever’s responsible may not live in the area, but knows the area well and comes across confident.

“They have very low self esteem, although they put on a very macho. He walks like he’s tough but really inside, he’s a coward,” Fleisher said.

Police sources say a special task force is assigned to the Kensington cases and are in the process of getting additional help from federal authorities, including a forensic profiler to get their suspect.

Reported By Elizabeth Hur, CBS 3; Todd Quinones, CBS 3

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