The search for evidence in the Gilgo Beach Murder case continues, as police have started to dig up Rex Heuermann’s backyard.

Rex Heuermann has been charged with killing three women who vanished in 2009 and 2010 – Melissa Barthelemy, Megan Waterman and Amber Costello.

A backhoe was brought to the property in Massapequa Park, Long Island and used for about three hours on Sunday morning, before being left overnight. The search is anticipated to continue during the week, with both cadaver dogs and ground penetrating sonar equipment. 

Law enforcement is currently investigating whether or not the suspect committed any of the murders inside of  his home, or if the bodies were ever there at all. It has been reported to ABC News that the police are still looking for evidence in that regard. According to phone records, police have ruled out the idea that Heuermann’s wife or two children were at home when the murders occurred. Those same phone records also show that the home is likely where the murders took place, though law enforcement was careful not to report that as fact.

Officials have also stated that rumors of a soundproof room are patently false. Suffolk County Police Commissioner Rodney Harrison told reporters Monday, “I believe that the soundproof room and the vault, that message got misconstrued, but there is a vault. There is no soundproof room.”

Harrison also reported that Heuermann had gathered a stockpile of assault weapons in the previously mentioned vault, though the purpose of the weapons remains unclear. 

Additional items removed from the home include a filing cabinet, large doll in a glass case, and a large portrait of a woman with a bruised face.

The BTK Killer has sent a letter to Fox, comparing himself to Heuermann as details continue to come out.

According to his attorney, Michael Brown, Rex Heuermann has denied killing the women.