Since I live in Arizona, I can tell you the following is a regular occurence:
Drugs enter the state through underground tunnels along with several illegals and are boarded into vans or onto trucks. These then travel to Phoenix area drop houses, some in very affluent neighborhoods, where the illegals are held hostage until their families send money to free them and the drugs are dispersed into smaller packages before being sent out into the city. The money collected from the sales of drugs and the ransom of kidnapped people is then collected and spent on firearms at gunshows or pawn shops along with the purchase of ammunition. These weapons then travel back to Mexico either through the same underground tunnels or through legitimate travel over the border. Sometimes additional money is made through stealing cars and identities (this happens even by mugging children in case they have a social security card on them).
This is a common enough occurence here in Arizona and has made this state the #1 state in the US for certain crimes: auto theft, identity theft, kidnapping, drug trafficking, human trafficking, and meth production.
Unfortunately Gunwalker does exist but so the illegals who mug children to get their identity.