PHOENIX – The sheriff for metropolitan Phoenix has launched a plan to have as many as 500 armed volunteers patrol areas just outside schools in an effort to guard against shootings like month's attack that left 26 people dead at a Connecticut elementary school.

Maricopa County Sheriff Joe Arpaio said Wednesday that he plans to have 400 posse volunteers and another 100 volunteers known as reserve deputies patrol 59 schools in unincorporated areas of metro Phoenix and communities that pay his office for police services. The patrols began Monday at some schools, though the number of schools wasn't immediately available.

The patrols from the sheriff known for immigration enforcement and housing jail inmates in canvas tents has led some longtime critics to say Arpaio's latest effort is meant to grab headlines and won't be sustained over the long term.