Read more: Craigslist is key to finding Long Island serial killer says top Irish cop

It is believed by some investigators that there could be more than just one Craigslist Long Island Ripper.

Authorities believe that differences in the way the ten bodies so far were disposed and the DNA, which includes a toddler in one instance, mean that there is more than one murderer.

Suspicion is also that 90s serial killer Joel Rifkin may have dumped bodies in the area according to The New York Post. Rifkin was caught when pulled over for a traffic stop and a dead woman was discovered in his trunk.

It is also now believed that the bundle of bones found on the beach, on Monday, are those of two people but they may be much older bodies dumped years ago.

The two killer theory goes to the notion that the area may have been a dumping ground for bodies for many years, known to only a few. It is wild, impenetrable and very difficult to find any evidence.

Nassau county executive Edward Mangano said the investigation headed by Irish-born Richard Dormer is looking for "an animal that has obviously taken the lives of a number of people".

According to sources there are a number of people being investigated in relation to the first eight murders. These include people in law enforcement or emergency service background and a familiarity with the area.

This is due to the fact that the killer phoned Melissa Barthelemy's 16-year-old sister but seemed to know to get off the phone before it could be tracked. He also made the call from a phone box in a crowded area. It has also been impossible to pick him up on CCTV.

The police are also looking into the possibility that the Long Island murders are connected to those of four prostitutes in Atlantic City in 2006. Officers now believe that the murderer has changed his techniques during his killing spree in order to avoid detection.

Authorities are also still searching for Shannan Gilbert the woman who sparked this huge manhunt. A 24-year-old sex worker who advertised on Craigslist, she was last seen 11 months ago on the beach shouting "He is trying to kill me".

Irish-born Police Commissioner Richard Drommer has insisted that the killers will be captured. According to the Independent's report he said "Computers and cell phones are what people communicate with today. That is what will track down this serial killer…If the guy made a mistake we'll find it."

As forensic anthropologists work on identifying the last four bodies the FBI behavioral analysis unit, crime scene investigation section, homicide squad and computer experts have also all been called in.
Dormer said "It is very difficult as the remains have been out there for some time…The ones identified -- and Shannan Gilbert the missing girl -- were all involved in the prostitution and escort business."

The Police Commissioner (71) who grew up in Laois said this is the biggest case he has been in charge of since leaving Ireland in 1958.

He said "I've seen just about everything. This is the biggest case I've ever handled, the eight bodies found in the area near Jones Beach. It's a massive investigation."

Dormer retired as a three-star police officer in 1993 before returning to head the Suffolk County department. Father-of-five, Dormer still keeps close contact with his sister Bridget Condren, brother Frank Dormer and his aunt Kathleen, who all still live in Crettyard, County Laois.

Read more: Craigslist is key to finding Long Island serial killer says top Irish cop