Monalisa Perez, 20, was urged by Pedro Ruiz III to fire a .50-calibre Desert Eagle handgun at him as he held a hardcover encyclopaedia against his chest at their home in Halstad, Minnesota last year.
In the video released by the Norman County prosecutor, Ruiz calls himself “the crazy Pedro” and said he wanted to see if a .50-calibre bullet could go through the book.
“The most trustworthy person that I trust in this world is my girlfriend, Monalisa,” Ruiz said in the video.
“So if I die, I’m pretty much ready to go to heaven right now.”
According to the transcript, Perez, who was pregnant with their second child at the time of the shooting, pleads with her boyfriend “I can’t do it, babe. I’m so scared.”
Ruiz tells her, “As long as you hit the book, you’ll be fine. Come on.”
“Babe, I’m not doing this, I can’t,” Perez said.
“Come on,” Ruiz replied.
“Babe, if I kill you what’s gonna happen to my life. Like no this isn’t okay,” she said.
“I don’t want to be responsible.”
The bullet went through the book, killing Ruiz.
Video of the shooting and aftermath were not released by Norman County Attorney James Brue, who called those portions “clearly offensive to common sensibilities”.
Perez, 20, of Redfield, South Dakota, was sentenced earlier this year to 180 days in jail for second-degree manslaughter.
Her sentence will be served in 30-day installments each year for six years.
A US prosecutor has released vision taken moments before a young mother fatally shot her boyfriend in a failed YouTube stunt.