On this weekend's "Sunday Square Off," Mesa Mayor John Giles defends his city's decision to hire a private prison operator to handle some of its inmates, a first for an Arizona city.

Giles said the decision was made for financial and safety reasons.

I ask him to explain why the private-prison contract is priced $1 million above the city's projected annual expenses, and why Mesa is now concerned about inmate safety at the county jail, when it took no action during the troubled reign of former Sheriff Joe Arpaio.

Also on "Sunday Square Off":

-2016 Arizona Teacher of the Year Christine Porter Marsh is taking on Republican State Sen. Kate Brophy McGee in next year's elections. It's her first run for office, but Marsh has plenty of experience in politics.

-On this Memorial Day weekend, Arizona State University professor and author Kyle Longley tells us what we don't know about the "grunts" who served and sacrificed their lives in Vietnam.

"Sunday Square Off" airs at 8 a.m. Sundays on 12 News, right after "Meet the Press."