I remember it being on TV around 2003-2005, I don’t think it was new at this time, but it definitely came out in the 90’s to that time. There were these prisoners in the desert, or near it and a zombie like prisoner was killing them with a pickaxe? I think it was one of the correctional officer’s dad or something. And he realizes it at the end, then something with blood seeping into concrete or something. The dead prisoner guy almost looked like Michael Myers, but his face was dry and dead looking. I think the correctional officer was a Hispanic actor.
Think it could be “Route 666”? The zombies are the prisoners, and the people are law enforcement, but it’s definitely in the desert and has a zombie armed with a pick axe.
Plus one of the zombies is the father of the hispanic law enforcement guy, and defends him from the other zombies.