I don't remember the case, but there was a book and movie about it, "Innocent Victims," by Scott Wisnant.
In May 1985, Kathryn "Katie" Eastburn and her two daughters, Kara, 5, and Erin, 3, were murdered in their home, on the outskirts of Fayetteville, N.C., near Fort Bragg. Police found the military wife next to her bed, raped and murdered. Two of her three daughters were also stabbed to death, their throats cut.
It would take 25 years to bring the man responsible for the grisly slayings to justice -- but not for a lack of trying. http://abcnews.go.com/2020/timothy-hennis-guilty-1985-triple-murder-trial/story?id=11652956Some said it seemed very odd that Hennis--if he were the perp--would commit such a heinous crime and then lead an exemplary life otherwise.
Maybe odd but it does happen. One of the perps in the Browns Chicken Massacre, a mass murder that occurred in 1993, did just that. The perps were Juan Luna and James Degorski. One of them, I can't remember which one, had pretty much led an exemplary life otherwise.
Brown's Chicken massacre
The Brown's Chicken massacre was a mass murder that occurred at a Brown's Chicken restaurant in Palatine, Illinois, a northwest suburb of Chicago, in the United States in 1993. The massacre occurred on January 8, 1993, when two assailants robbed the Brown's Chicken restaurant and then proceeded to murder seven employees. The case remained unsolved for nearly nine years, until one of the assailants was implicated by his girlfriend in 2002. http://en.wikipedia.org/wiki/Brown's_Chicken_massacre