20/20 · Season 48

First Comes Love, Then Comes Murder

When a wife and mother named Leslie Preer was killed in her house in Chevy Chase, Maryland, in the spring of 2001, shockwaves were sent across the entire community. Her loved ones had to wait for justice for more than two decades until the detectives apprehended the killer using an advanced DNA technology. The investigation revealed a dark truth that connected the killer to the Preer family.