Authorities investigating a suspected serial killer are planning what they say will be a "significant" update Monday afternoon on human remains found last month behind the same strip mall where the partial skeletons of three women were discovered in 2007.

Police found the remains April 28 behind a New Britain shopping center where the partial skeletons of 53-year-old Diane Cusack, 23-year-old Joyvaline Martinez and 40-year-old Mary Jane Menard were discovered eight years earlier.

It's not clear whether the newly discovered remains belonged to any of the three women. New Britain Police Chief James Wardwell, state prosecutors and officials with the chief medical examiner's office declined to discuss the case Monday morning.

Police have said they believe a lone killer is responsible for the three women's deaths. The state is offering a $150,000 reward -- $50,000 in each cold case -- for information leading to a conviction.

Wardwell has said Cusack, Martinez and Menard had drug problems. All three women were last seen in the late summer or early fall of 2003 and were known to frequent the same downtown New Britain neighborhood.

A person looking for a place to hunt discovered human remains behind the shopping center in August 2007. Authorities searched the property and found the three women's remains.

Cusack, of New Britain, had been out of contact with her family for years and was never reported missing, police said.

Martinez was last seen in October 2003. Her family has said she was unemployed and living with her mother, and relatives became concerned when she didn't show up for her birthday party.

Menard, of New Britain, was a substance abuse counselor who had a daughter serving oversees in the military when she disappeared that same October, police said.

In a strange coincidence, the body of a 17-year-old girl, later identified as Elizabeth Honsch, was found behind the same strip mall in 1995. A week later, the body of her mother, 53-year-old Marcia Honsch, was found near an entrance to Tolland State Forest in western Massachusetts. Both had been shot in the head.

Police have said they don't believe those two killings are related to the cases of Cusack, Martinez and Menard. Robert Honsch, Marcia's husband and Elizabeth's father, was charged with murder and awaits trial.