Suppose, for a minute, that you’re Joe Garcia, the deputy agent in charge of the San Diego office of Immigrations and Customs Enforcement. You’ve just got word that your Border Tunnel Task Force has found a drug smuggling tunnel that’s clearly coming from Mexico. What you know about the tunnel: Somebody spent close to $1 million to build it -– tunnels usually turn up after neighbors have alerted police to truck traffic at unusual hours — signs that bales of marijuana are being loaded onto trucks and moved out of warehouses on the U.S. end. You know that it’s the work of a drug cartel –- these days mostly Sinaloa -– so you can assume dangerous people are involved. What you don’t know: where the other end is, who’s in it, what they’ve left behind

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As the Drug War Goes Underground, Feds Call in the Robot