A convicted prostitute who stole a memory card from a date was horrified to find gruesome footage of a woman being beaten and strangled — with the stolen card now at the heart of a double-murder trial.

The unidentified thief stole the SD card from the center console of a date’s truck during a date in Alaska — handing it to police a week later after discovering the horrors it contained, according to court documents in the trial of Brian Steven Smith, a 52-year-old new US citizen.

It was labeled “Homicide at Midtown Marriott” — and contained nearly 40 photos and a dozen videos of Kathleen Henry, 30, being beaten and strangled in 2019 and then smuggled out of the Anchorage hotel under a blanket on a luggage cart, the documents say.

It included the killer stomping on her throat and saying, “You need to f–king die, bitch.”

“In my movies, everybody always dies,” said the man. “What are my followers going to think of me? People need to know when they are being serial killed.”

Photos also showed Henry “lying on a floor next to a bed … completely naked and on her back,” according to charging documents obtained by South African outlet IOL.

“The man in the recording talks, saying things as ‘My hand’s getting tired’ and he proceeds to stomp on the female’s throat with his right foot,” the documents say.

“The male can be heard saying ‘You need to f–king die, bitch’ and ‘just f–king die.’”

Police recognized married South African native Smith’s distinctive voice from a prior investigation, the court documents say.

Authorities believe the footage was taken at the TownePlace Suites by Marriott in Anchorage — where Smith was registered to stay from Sept. 2 to 4, 2019.

The first images showing Henry’s body were timestamped around 1 a.m. Sept. 4 — when he was still at the hotel — and the last were from early Sept. 6, showing Henry’s body in the back of a black Ford Ranger pickup truck like the one Smith owned, the documents allege.

Smith’s phone was also traced to the area where Henry’s body was later found.

While being interrogated about Henry’s death, Smith allegedly also admitted to killing Veronica Abouchuk, 52 — and provided authorities with the location of her remains.

Smith’s phone was also traced to the area where Henry’s body was later found.

“With no prompting, he tells the troopers in the bathroom, ‘I’m going to make you famous,’” District Attorney Brittany Dunlop said at a court hearing last week.

“He comes back in and says, ‘You guys got some more time? You want to keep talking?’ And then he discloses this other murder.”

Abouchuk was 52 when her family formally reported her missing in February 2019, several months after they had last seen her. Like Henry, she had been through periods of homelessness.

Alaska state troopers in 2018 had incorrectly identified another body as that of Abouchuk, because Abouchuk’s ID had been discovered with it, for reasons that remain unclear.

But dental records later confirmed she was the woman whose skull was found with a bullet wound where Smith told cops to look, authorities have said.

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