Gladys Machado Update: Alberto Sierra, estranged husband, confessed to killing Fla. mom and her daughters, police say

Alberto Sierra
CBS Miami/ Miami-Dade Police
Alberto Sierra
CBS Miami/ Miami-Dade Police

(CBS/WFOR) MIAMI - Police say the estranged husband of Gladys Machado, who was found dead in the closet of her Miami-area home next to the bodies of two of her children, has confessed to raping and killing her and her 8-year-old daughter as well as to killing her other young daughter, CBS Miami reports.

PICTURES: Fla. mom, 2 kids found dead in closet

According to the station, 28-year-old Alberto Sierra is charged with three counts of first degree murder, one count of sexual assault of an adult and one count of sexual assault of a child.

The arrest affidavit says on November 10, Sierra went with Machado and her two daughters, 4-year-old Daniela and 8-year-old Julia, to the Mall of the Americas, where the couple got into a fight, CBS Miami reports. Sierra reportedly pulled a knife and Machado was injured.

Sierra allegedly forced the three into their house and locked the girls in a bedroom, according to the station. Sierra took Machado to the master bedroom where he reportedly suffocated her with a plastic bag and sexually assaulted her.

According to the Miami Herald, Sierra called the older girl into the master bedroom then raped and suffocated her, the arrest record states. He then returned to bedroom and suffocated the second girl while she slept.

The Herald reports that arrest records show Sierra was accused of domestic battery against Machado in 2010, when he allegedly bit her during an argument and stole her gun. She later claimed she found the gun, and that it had not been stolen.

When officers found Sierra two months later, the Herald reports he was arrested for having 79 grams of ecstasy and a gun police say he admitted stealing during a burglary. He was sentenced to a year of probation, which was revoked in November 2011 when police investigating another burglary found weapons in the home where he lived with Machado.

He served 364 days and was released on June 22 this year, CBS Miami reports.

Complete coverage of Gladys Machado on Crimesider