WOULD A HUSBAND DRUG HIS KIDS SO THEY WOULDN'T HEAR HIM KILL HIS WIFE? "48 HOURS": "SHATTERED DREAMS" SATURDAY, JULY 6, 10:00 PM, ET/PT

Maureen Maher and 48 HOURS examine the death of Karina Ditto, a married mother who fell down a flight of stairs in 2011 and died two days later in this update of "Shattered Dreams," to be broadcast Saturday, July 6, 2013 (10:00 PM, ET/PT) on the CBS Television Network.

Karina and David Ditto appeared to have it all. They met when he vacationed in Mexico in 1993. They fell in love. She moved to the United States, where they married and had kids. But the investigation into the death of Karina exposed a troubled marriage and allegations of extreme emotional and control abuse inflicted by the man of her dreams - David.

It all unraveled after David called 911 in March 2011, saying his wife fell down the stairs and smacked her head on a tile floor. First responders were immediately suspicious of David's version of what happened.

"I heard the cat screech at the top of the stairs and I heard a horrible falling down the stairs," he tells 48 HOURS. "And I jumped up and ran over, and found Karina laying at the foot of the stairs. She wasn't moving - wasn't talking."

The San Diego County medical examiner ruled Karina was beaten and strangled, and soon after David Ditto was charged with his wife's murder. The investigation exposed red flags that suggested Karina's death was no accident. Moreover, investigators learned Karina had written letters to her mother saying David would tell her which spoon to use, when to eat and how much water to use for houseplants. "He punishes me with money, he takes it away for months," Karina wrote to her mother.

Homicide Detective JC Smith tells Maher that police also questioned why the children, asleep upstairs in the home, never woke up given the number of EMS, fire and police workers in the home. "David had access to narcotics, and we thought, possibly, he used the drugs on his kids," Smith tells Maher. "Absolutely not," Ditto says.

This updated rebroadcast of "Shattered Dreams" is produced by Deborah Grau, Gayane Keshishyan and Alec Sirken. Sarah Denlinger is the associate producer. Ken Blum, Maria Barrow, Mike Mongulla and Marlon Disla are the editors. Suzanne Allen is the senior coordinating producer. Linda Martin is the update producer. Anthony Batson is the senior broadcast producer. Susan Zirinsky is the senior executive producer.