Snatch-and-grab thieves stole about $19,000 worth of watches from a department store in just 13 seconds, police said.

Surveillance video shows the three thieves in action at the Macy's at Firewheel Town Center in Garland, Texas, on Nov. 5.

Investigators said they believe the thieves had been casing the store. The three watch carousels were chained to a display counter, but the thieves were strong enough to rip them off and take off running, police said.

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"These people knew what they were doing," Garland police spokesman Officer Joe Harn said. "They had been in and knew what they were going to do. They were in and out very quickly."

Witnesses said the trio fled in a green sedan that was followed closely by a white pickup truck.