A televised dispute over an engagement ring turned into one of Florida's most haunting missing persons cases. This week, CBS News correspondents Shanelle Kaul and Cristian Benavides examine the recent arrest of Michelle Parker's ex-fiancé, Dale Smith Jr., 15 years after her disappearance, and hear from the family members who never stopped fighting for answers.

In 2012, Lizzi Marriott was a 19-year-old New Hampshire student when she disappeared after visiting her co-worker, Kat McDonough, and Kat's boyfriend, Seth Mazzaglia, in their apartment. Kat initially claimed Lizzi's death was accidental, but later testified that Seth strangled Lizzi with a rope after she rejected his sexual advances. "48 Hours" correspondent Troy Roberts reports.

This classic "48 Hours" episode last aired on 9/19/2015. Watch all-new episodes of “48 Hours” on Saturdays and stream on demand on Paramount+.

On August 16, 2009, 9-1-1 operators received two separate calls from the same house. A husband and wife had each dialed in, claiming their partner had stabbed them. When the husband died of his wounds, investigators were left wondering if the killing was self-defense or a cold-blooded murder. "48 Hours" correspondent Peter Van Sant reports. This classic "48 Hours" episode last aired on 9/3/2011. Watch all-new episodes of “48 Hours” on Saturdays and stream on demand on Paramount+.