The mother of murdered model Christy Giles pleads for others to share their locations. She says the technology helped police catch David Pearce, who murdered Giles and her friend, architect Hilda Marcela Cabrales.
David Pearce was convicted of first-degree murder for the deaths of Christy Giles and Hilda Marcela Cabrales after a night of partying in Los Angeles. He was also found guilty of raping seven other women who came forward to testify at his trial.
A man charged with murder for poisoning two women tells a friend, "dead girls don't talk." Brave survivors speak out on their behalf. "48 Hours" contributor Jonathan Vigliotti reports.
