In March 2011, David Ditto called 911 to say his wife, Karina, had fallen down a flight of stairs in their Mira Mesa, California home and slammed her head on a tile floor. Karina died two days later, and the medical examiner ruled that she was beaten and strangled. Investigators believed David drugged his two children so they wouldn't wake up during the murder. “48 Hours" correspondent Maureen Maher reports. This classic "48 Hours" episode last aired on 7/6/2013. Watch all-new episodes of “48 Hours” on Saturdays, and stream on demand on Paramount+.