Friday, April 23: An obesity defense, and a double life

A wealthy executive is gunned down in his home.  His former in-law charged with the murder.  But what really made national news was the suspect's defense:  he said he was too fat to have killed. But would the argument -- and the science behind it -- sway the jury?  Dateline NBC's Dennis Murphy reports.

After losing control at the wheel, a loving mother dies.  Her death would shatter what everyone thought was a perfect family life - especially after her husband mysteriously disappears and his double life is exposed.

See it this Friday at 9 p.m. ET, 8 p.m. CT.