After six weeks of searching for 13{ tons of stolen coffee, this was the break authorities were looking for. A police officer became suspicious of a trailer that had been parked along a freeway for nearly two weeks in this San Bernardino County city and ran the license plate through a computer. The computer found nothing wrong, but the notion that something wasn't quite right kept percolating in Officer Tim Lane's police mind. Finally, on Saturday, he ran the trailer's vehicle identification number, and the case of the missing Folgers was cracked. The computer showed the refrigerated trailer was stolen last April in North Hollywood. Inside, officers found about 9,000 three-pound packages of Folgers, which was unloaded Monday. Capt. George Westcott said police traced the lot numbers of the coffee and determined it had been stolen May 2 in San Francisco. It was not immediately known why the coffee was abandoned.