Christopher Birch is a young man who was murdered by three police officers.
For an unknown reason, Christopher was pulled over by officers Gerald Hatch, Toby Gray and Ed Colfax. During the traffic stop, the three officers shot Christopher in the head and murdered him. As Christopher was unarmed, the three cops planted a gun on him to justify their murder. Despite demands by Christopher's father Darrel, no investigation was launched into Christopher's death.
A month after Christopher's murder, his younger brother, Aaron, desperate for justice, prayed to God for help. While God didn't answer Aaron's prayers, the angel Balthazar did. In exchange for Aaron selling his soul, Balthazar gave Aaron a piece of the Staff of Moses to exact revenge upon Christopher's killers.
Using the Staff of Moses, Aaron inflicted three of the Plagues of Egypt upon Christopher's killers, brutally avenging his murder. Before Colfax died, he told hunters Sam and Dean Winchester that they deserved what happened to them because of Christopher Birch, "a kid with no face and a planted gun." Driven insane by the deaths of his friends and the locusts eating his brain, Colfax also scratched out all the faces in the pictures in his house.
After Colfax's death, Sam discovered the report on Christopher's death and the Winchesters realized what had really happened. With the help of the Seraphim Castiel, the Winchesters were able to further link the murders of the cops to the Staff of Moses and Christopher's brother Aaron though they had initially believed the killer to be his father Darrel. After a fight with the archangel Raphael and his followers, the Winchesters were able to force Balthazar to release his claim on Aaron's soul, ensuring that he would suffer no consequences for avenging Christopher.