Alberto Sierra's mom takes the stand in his death penalty trial for murder of wife, 3 girls

Alberto Sierra, 42, became emotional as his mother took the stand. Sierra pleaded guilty in August to the 2012 murders of his estranged wife, 29-year-old Gladys Machado, and her two daughters, 6-year-old Julia Padrino and 3-year-old Daniela Padrino, after suffocating all three with a plastic bag. A jury will now decide whether he will face the death penalty.