Green’s Dictionary of Slang

1. a general derog. term of abuse; thus baby-raping adj., of a person, despicable, disgusting.

1961		(con. early 1950s) J. Peacock Valhalla 45: ‘Sounds like you don’t like him,’ Giff grinned. Poke snorted. ‘The baby raper cost me two months at the brig.’.
1996		A. Proulx Accordion Crimes 79: He went defiantly into town on Saturday and was stoned by a gang of boys and young men who shouted ‘heinie!’ and ‘fucken dirty Dutchman!’ and ‘baby raper!’.

2. a paedophile, a child molester.

1967		M. Braly On the Yard (2002) 12: He thought of them in terms of their crime: Two Checks, a Manslaughter, a Burglary, a Baby Raper.
1976		Helfer & Kempe Child Abuse and Neglect 148: His fellow inmates call him a ‘baby-raper.’ No one is more despicable. He is segregated and often subjected to indignities and violence.
1989		in K. Brohl et al. When Your Child Has been Molested 33: All I could think of was that I’d married a baby-raper, and that I must be not only stupid but a bad person.
1992		P. Earley Hot House 8: ‘Fuck yes, he’ll cooperate, because if he don’t we’ll tell everyone he’s a baby-raper and they’ll kill his ass’ .
2008		D. Stabenow Deeper Sleep 299: Kate [...] had earned her scar confronting another baby raper in another city.
2021		T. Pluck Boy from County Hell 85: ‘At least you ain’t got a baby-raper cleaning shit out your ass’.