Within two weeks, about half of St. Louis County police officers will be recording every call for service using tiny video cameras on their chests, glasses or collars.

Several companies are lending free technology to police departments in hope of landing lucrative contracts in an industry that surged after a national outcry about the Ferguson police shooting. In St. Louis County, 188 police officers will be using cameras in the north and central county precincts, as well as in Jennings and Dellwood, the St, Louis Post-Dispatch reports.

About two dozen officers from the county police received cameras and training on Tuesday. Chief Jon Belmar said his goal is to have all 465 patrol officers wearing them as soon as possible.

For the next 90 days, the department will experiment with different types of cameras and approaches. Some officers will be assigned cameras, some will share among shifts. The experience will help officials decide which devices to buy, and how many.