Crabtree

Crabtree was a police officer working in London in 1953.

He and Detective Inspector Bishop were tasked with investigating the mystery of the humans made faceless by the Wire. (TV: The Idiot's Lantern)

Personality
Unlike Bishop, Crabtree was plain-clothed, thuggish, and far from talkative. He was also not afraid to use violence; he knocked out the the Doctor with a "hell of a right hook" before the Doctor could talk to him. He was also somewhat dimwitted, as he tried to close his hand over his elbow when the Doctor said it was impossible. (TV: The Idiot's Lantern)