James Howson, 25, of Doncaster received a life sentence Friday and must serve a minimum of 22 years, The Yorkshire Post reported. Justice Laura Cox called his crime "a brutal and chilling attack."
"Exactly what happened that caused you to do what you did on that night remains unclear," Cox said. "At some point, probably because she was in pain or distress you placed Amy on your knee and then deliberately pushed her down on some object or on you knee, fracturing her spine."
During the sentencing hearing, the court heard of Howson's history of violence against women. His lawyer, Adrian Waterman, read a report from a teacher when he was expelled from school at the age of 14.
"This boy will commit a murder before too long," the teacher said. "I have never seen a such a disturbed young man."
Howson's girlfriend, Tina Hunt, was given a 12-month suspended sentence for failing to report the abuse of their daughter.