Identifying Features, from first-time director Fernanda Valadez, is like water in the desert for the mostly myopic genre of "la frontera" action films that depict the migration crisis at the southern border of the United States. Shot on location in rural Guanajuato, Mexico, this poignant film (which scooped two awards in the World Cinema Dramatic Competition at this year's Sundance fest and will be distributed in the U.S.