Investigators Thursday morning are starting to comb through a key piece of evidence in the Gilgo Beach murder case.

The Suffolk District Attorney’s Office says the pickup truck that brought police to Rex Heuermann is now at the county crime lab.

The DA’s office says the vehicle, a green Chevy Avalanche removed from his South Carolina property, is believed to be the one he owned around the time of the murders.

Heuermann owns a plot of land near his brother’s residence in Chester, South Carolina. During the investigation and prior to the arrest, the Chester County Sheriff’s Office was requested by the Gilgo Beach Task Force to assist in gathering evidence at the property relevant to their investigation.

Officials told News 12 that Suffolk criminologists are going through all areas “literally inch by inch” to obtain evidence.

“This is a painstaking process. It is a long process and we are going to let that process play out,” the DA’s office said. They added that they will have more to say when the analysis is completed.

Investigators linked Heuermann's vehicle to a cluster of calls they say he made from near his Massapequa Park home.

Investigators say it was one of the clues that led their focus to Heuermann as a suspect and later to charge him in the murders of Megan Waterman, Amber Costello and Melissa Barthelemy.

News 12 Long Island crews noticed Thursday morning that police have almost completely blocked Heuermann’s Massapequa Park home, and media members were moved a block back from where they previously were.

Michael Brown, Heuermann’s court-appointed defense attorney, said on Friday that his client was “distraught” by the arrest.

“The only thing I can tell you that he did say as he was in tears was ‘I didn't do this,’” said Brown. “It’s important that when someone is charged with a crime, you have to afford the presumption of innocence.”