Dateline: Unforgettable Season 4

A chance encounter on the Pacific Coast Highway with a woman he first spoke to in a jail cell leads Keith Morrison to re-examine the mysterious death of Las Vegas casino magnate Ted Binion.

When Dr. Joe Sonnier is murdered, the investigation reveals simmering jealousies and a love triangle; Andrea Canning recalls a doctor who dedicated his life to helping others.

A pastor's secrets come to light, triggering a murder investigation; Josh Mankiewicz looks back at a case that shattered a congregation and exposed the cost of their trust.

When a woman is found dead in her SUV, the investigation into her murder reveals a tangled web of sex and lies. Dennis Murphy looks back on his unusual interview with the lead suspect.

Chris Smith's family receives an email stating that he is leaving California to surf the world; months later, they wonder if he really left. Keith Morrison offers new insights into the case.