The sole witness was the man driving the couple home

A 31-year-old man is facing murder charges in Seattle, where authorities allege he fatally shot his wife as the two argued while heading home early Sunday in an Uber car, PEOPLE confirms.

According to a statement from Seattle police, 29-year-old Jennifer Espitia was shot once in the head as she sat in the front passenger seat of an Uber vehicle.

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In the backseat, police allege, was her husband, Cameron Espitia, who is being held in a Seattle jail on $3 million bail.

On Monday, during his arraignment, prosecutors characterized the alleged crime as an “execution,” reports the Seattle Times.

The sole witness was the man who was driving the couple home.

Investigators spoke with the driver, who told them he heard a loud pop, and assumed one of his tires had blown out, PEOPLE confirms with a law enforcement official. But then, the woman who was sitting in the seat next to him slumped over. At that point, he knew she had been shot.

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The driver told police the couple got into an obscenity-filled argument soon after getting into his car minutes after midnight.

According to police, the Uber driver feared for his life and continued driving to appease Espitia, who eventually ordered him to pull over to the side of the road.

After Espitia exited the vehicle, the driver went directly to the nearest hospital, where the woman was pronounced dead.

It didn’t take long for Seattle police to track Espitia down. He allegedly told detectives he and his wife had been drinking in the hours before ordering a ride home. While searching Espitia, police allegedly recovered a small pistol from an ankle holster he was wearing.

Espitia allegedly told police he blacked out and had no recollection of what happened, and awoke confused in a thicket of bushes.