I have an engineer friend who has a heart of gold. He refurbished about 15 computers and made arrangements with a church in Baja California to donate the computers for a computer lab for the underprivileged. He and a friend loaded the computers in his friend's van and headed south.
They got as far as the border. At the custom's check, they told the Mex. govt. agents what they were going to do. The Mexican authorities confiscated the computers and the friend's van, kept them a couple of hours then let them go, without computers or van.
I would not be too surprised if the Mexican police and criminals in these robery cases are one and the same.
Last year 2 young USA women were kidnapped in Nuevo Loredo. The Mexican authorities kept saying they were 'working on it'. Later one of the fathers went to the police station and found his daughter's car in the impound yard.