New details of serial killer Rex Heuermann’s sick torture routine inside his basement “kill room” was too much for one relative of his helpless victims to bare.

“I can’t!” the woman screamed as Suffolk County DA Ray Tierney began describing Heuermann’s monstrous crimes in a Riverhead courtroom where the killer was sentenced to life in prison.

“When he talks about what he needs to dispose of, he talks about props, toys, wood items,” Tierney told Judge Timothy Mazzei. “Wood items that he made himself with members of his own family that he kept in his house and he used during the execution of these murders, only to destroy them.

“He’s treating this as if it were a sport,” the prosecutor said. “The talking of lives as though it were a sport.”

Heuermann, who pleaded guilty in April to strangling and dismembering eight sex workers — all but one in a “kill room” in the basement of his family’s Massapequa Park home — was slapped with three life terms.

The hulking architect killed the women between 1993 and 2010, with the cases unsolved until he was arrested outside his Manhattan office in 2023.

Suffolk County prosecutors said Heuermann kept a meticulous “planning document” on his computer, where he kept gory notes on how to prepare to “hunt” his victims and torture them to death.

The victims, all young and petite sex workers, were discovered in remote areas in Gilgo Beach and in Manorville in 2010 and 2011.