Former Sheriff Joe Arpaio says he's being unfairly blamed for releasing from custody a Mexican immigrant featured in a Donald Trump political ad that shows the man in a California courtroom bragging about killing police officers.

The ad centers on Luis Bracamontes, who was convicted in the 2014 shooting deaths of two California officers in while Bracamontes was in the U.S. illegally.

More than a decade earlier, Bracamontes was incarcerated four times in jails run by Arpaio, who is known for his crackdowns on illegal immigration.

Arpaio says Friday that he hasn't seen the ad and didn't remember details of the cases.

But he says his officers likely contacted federal authorities to pick up Bracamontes, because that was the procedure in the jails at the time.