for bergen county prosecutor john molinelli, that was a disturbing development. that's because this was now the arson homicide in bergen county in less than a year. >> are those other two murders the first thing that come to your mind when you see this crime scene? >> there was certainly a discussion and a deliberation on the topic, certainly within the first few weeks of the cantor murder. >> reporter: on the surface, there were haunting similarities. in april of 2010, 69-year-old dolores alliotts had been found stabbed to death in her burning home. she was a woman that was known to leave her house open. she did not lock her doors. it could have been a stranger from the street. >> reporter: a few months later, 74-year-old joan davis, a well known community activist -- seen here at a teaneck city council meeting -- was found strangled and stabbed to death in her burning home. >> we had always believed that the person who murdered joan davis was someone that she let into the house. >> reporter: and now, rob cantor had been found dead in his burning home -- also in