Occasionally, an art exhibit has exquisite timing. Such is the case with “The Fence,” an exhibit of photographs by Charles Ommanney at Leica Store D.C.

At a time when immigration from Mexico is driving much of the debate in the 2016 presidential race, Ommanney’s documentary series on the U.S. Mexico border region—ranging from Brownsville, Texas, to Friendship Park, Calif.—shines a light on the people and landscapes of this troubled divide.

The “fence” in question is often, but not always, a physical object, as it is in a stretch between Yuma, Ariz., and Calexico, Calif., where it travels into the distance like a long-tailed reptile (above). Other times, the structure stops abruptly—and inexplicably—as it does when it overlooks a rugged hillside filled with modest homes. And at times, the international border is apparently marked by nothing more than a row of sticks inserted into the ground.

Ommanney, a British-born international photojournalist, also offers some thoughtful studies of people whose lives have been circumscribed by the border. One affecting image depicts a gloomy teenaged girl whose backyard access to the Rio Grande has been cut off due to recent border fortifications. Another image features a migrant who walked from Guatemala yet was apprehended by officers just 300 yards into the United States; the man kneels before the uniformed patrols, his hands covering his eyes, in a pose that comes disturbingly close to what a man awaiting his execution would look like.

Not to be overlooked, though, are the seemingly minor visual details the photographer has discovered, and from which he has extracted significance. One image shows a hand-rigged contraption consisting of three vehicle tires; patrol officers regularly attach it to a truck and drive over heavily trod swaths sand to wipe out old footprints and aid in determining how many people have attempted to cross since.

Ommanney’s most enigmatic photograph depicts an empty cage within sight of a section of the wall. Like his strongest work, the image leaves its full meaning to the imagination; like the series as a whole, it provides no easy answers for tackling this urgent policy issue.

Through Jan. 22 at the Leica Store D.C., 977 F St. NW, Washington, D.C. (202) 787-5900. Mon-Wed 11-6, Thu-Fri 11-7, Sat 11-6.