John Slattery. Actor: Spotlight. John Slattery was born and raised in Boston, Massachusetts, the son of Joan (Mulhern), a CPA, and John "Jack" Slattery, a leather merchant, both of Irish descent. John landed his first TV gig on the 1988 series The Dirty Dozen (1988) and has worked steadily since then. His television career has included the short-lived series Under Cover (1991), Homefront (1991), Maggie (1998) and Feds (1997); and...