F Troop Does Real Police Work (Sometimes): A new effort to combat a rash of home invasion-style robberies in Phoenix by teaming federal agents with the police has resulted in the arrest of 70 people since May and crimped the operations of several groups behind the crimes, the authorities said Tuesday. Home invasion robberies and kidnappings, largely tied to the smuggling of drugs and people across the Mexican border, have been persistent problems in Phoenix and other cities near the border. Officials with the federal Bureau of Alcohol, Tobacco, Firearms and Explosives said a “unique” unit of federal agents has worked with Phoenix detectives to break the robbery crews, which have included attackers dressed in dark uniforms and masks similar to police tactical units…

They started slowly, infiltrating the vast Phoenix drug market with a team of all-stars, handpicked from around the nation. The federal agents came to Phoenix prepared to take on the rising tide of drug-related violence, where armed criminals are ready to kick in doors, rob armed drug-runners and shoot anyone who gets in the way. Their plan: Go undercover, lure in the violent crooks by soliciting them to rob drug dealers, then take them down. In the end, Bureau of Alcohol, Tobacco, Firearms and Explosives agents arrested 70 people, seized about $39,000 and took dozens of guns and other weapons off the street, authorities said Tuesday. The arrests were only a dent in the problem, they said. What surprised them most was the number of people they found ready to join complete strangers for robbery and murder in Phoenix's drug underworld…