The Gauntlet (1977)6.4 /10

Storyline:  In Phoenix, Detective Ben Shockley is tasked with escorting witness Gus Mally from Las Vegas. What seems like a routine job turns into a deadly mission when Shockley discovers Mally is set to testify against powerful criminal interests. Betrayed from within, they hijack a bus and armor it to survive a brutal ambush by the very police meant to protect them.