Monalisa aimed her gun at her boyfriend and begged him to call off his YouTube stunt.

Her heart beating rapidly, tears welling, Monalisa Perez clutched the .50-caliber Desert Eagle pistol.

“I can’t do it babe,” the pregnant 20-year-old said.

“I’m so scared… Babe, if I kill you what’s gonna happen to my life? Like no, this isn’t OK. I don’t want to be responsible.”

Her partner, YouTube star Pedro Ruiz III, was standing in front of her at point-blank range, holding an encyclopedia over his chest like a shield.

“As long as you hit the book, you’ll be fine,” he urged. “Come on.”

According to a transcript released for the first time on Friday by the prosecutor in Norman County, Minnesota, those were among the last words Ruiz uttered. As roughly 30 people, including the couple’s three-year-old daughter watched on that June day in 2017, the bullet pierced the pages of the 3.8cm-thick book and entered the 22-year-old’s body.

The fatal shot was captured by two cameras Ruiz had set up outside his Halsted home to record the stunt, which he hoped would go viral once shared online.

In her interview with the Minnesota Bureau of Criminal Apprehension, Perez said Ruiz had tested the safety of the concept by firing on various books in an abandoned building. To prove it, Perez said, he showed her a bullet lodged in the pages of one of the test books.

Still, as Perez tweeted ahead of filming, it was "one of the most dangerous" acts he and Perez had ever performed for their YouTube channel.

The couple were up-and-coming in the crowded vlog arena, thanks to their brazen pranks, which included Ruiz unsuspectingly eating a sandwich containing one of the world’s hottest chillis and being fed a doughnut topped with baby powder.

Me and Pedro are probably going to shoot one of the most dangerous videos ever???????? HIS idea not MINE????

— Monalisa Perez (@MonalisaPerez5) June 26, 2017

According to Fox9, Ruiz began his final video by expressing his complete faith in Perez.

“The most trustworthy person that I trust in this world is my girlfriend, Monalisa. So if I’m going to die, I’m pretty much ready to go to heaven right now. If I die, I’ll be ready for Jesus,” he said.

“He probably won’t accept me into the pearly gates because of how stupid this is, but I have confidence that my girlfriend will hit the book and not me."

Perez pleaded guilty to second-degree manslaughter and was sentenced in March to 180 days in jail. Her sentence will be served in 30-day instalments each year for six years.

In her police interview, she told investigators she didn't mean to hurt her boyfriend.

"He was my everything," she said. "It wasn’t supposed to happen like this”.