Two steps ahead of the police
A day of reckoning is in store for law enforcement. The band of criminals they are about to encounter can easily overpower them. More importantly, these bandits are deft at staying at least one step ahead of the police.
The robbers terrorize Las Vegas then move on to Texas. These guys aren't people you want to make mad. The police will have their hands full trying to apprehend them because they're clever and possess dangerous guns. The longer they're on the street and antagonized by hostages, the meaner they become and the more the community is in danger.