| ||For other characters named "Carter", see Carter.|
In May 2229, Mr. Carter entered Diamond City and joined others at a bar, claiming to be from the west. After three hours and four-five drinks, Mr. Carter suddenly lost his smile and his cheek began twitching. He then drew a revolver and calmly shot the barman, Henry, in the head. He continued shooting, killing another three to four people, before being killed by Diamond City security. Upon inspecting his corpse, the witnesses discovered the plastic and metal underneath, revealing that Mr. Carter was actually a new generation of synth.
This event, later known as the "Broken Mask incident," led to the people of the Commonwealth learning of the existence of synths nearly identical to humans. Later, in 2287, journalist Piper Wright would write an article on the event, The Synthetic Truth.
According to Director's recording #108, Mr. Carter was a prototype synth and was not ready for field testing, implying that the massacre was the result of the synth malfunctioning.
Mr. Carter is only mentioned in Fallout 4.