SAN DIEGO (AP) — No criminal charges will be filed against any of the 42 people associated with a caravan of Central American migrants who were arrested in a clash that ended with U.S. authorities firing tear gas into Mexico to counter rock throwers, The Associated Press has learned.

The decision not to prosecute came despite President Donald Trump's vow that the U.S. will not tolerate lawlessness and after extensive preparations were made for the caravan, including deployment of thousands of active-duty troops to the border.

Charges were not filed because the administration generally doesn't...