48 Hours: Hard Evidence

After the murder of a Texas woman, investigators discover that finding a suspect is only a part of this complex story.

Officers arrive at a nurse's apartment to find her lying dead in the bathroom; a security camera captures her coming home for the last time; can authorities piece together the evidence to determine if this was suicide or murder?

After a toddler dies at daycare, police arrest a young worker; she confesses, but years later, questions still swirl; learn whether her statement was reliable or if the key evidence misled the jury; investigators revisit a case that refuses to rest; Erin Moriarty reports.