San Diego mosque killer Caleb Vasquez urged his accomplice to shoot him in the head in a twisted exchange captured on a livestream broadcast shortly after the pair murdered three people.

Vasquez, 18, is seen in the passenger seat of the white BMW that he and 17-year-old Cain Clark used to flee the Islamic Center of San Diego. The footage was captured by a dashcam the pair had placed on the car while the vehicle was stopped.

In the livestream clip, Vasquez repeatedly grabs the barrel of Clark’s rifle and presses it against his own forehead. The video, which is circulating on social media, has no audio.

Finally, the camera pans to show only Clark in the driver’s seat. He uses his pistol to shoot Vasquez in the head twice, then turns the gun on himself.

The FBI is currently investigating the livestream video, law enforcement sources told The Post.

The livestream also captured the two teen terrorists arriving at the Islamic Center and opening fire. During the attack, both wore Nazi-style gear, including the Black Sun symbol, which is associated with Nazi Germany. Nazi SS commander Heinrich Himmler had the symbol inlaid into the floor of Wewelsburg Castle.

The attackers had also written hate messages on their weapons, including the phrase “Race War Now.” Before carrying out the terrorist attack, the pair left behind a hateful manifesto that praised Adolf Hitler and a number of other mass murderers.

Three men, including the center’s security guard Amin Abdullah, were killed in the attack.

At a press conference on Tuesday, Abdullah’s daughter, Hawaa Abdullah, paid tribute to her father:

“To me, my dad was a role model. He was a best friend. He was the best, absolute best dad in the world. He was my protector. If I needed help, anything,” she said.