The Walmart on Gateway Boulevard in El Paso is where a 21-year-old man from across the state, driven by his anger at a “Hispanic invasion,” showed up last Aug. 3 on a murder mission. Firing an assault rifle, he killed 22 people and injured another 24.

Last month, the Mexican artist Teresa Margolles made a pilgrimage to the scene. Ms. Margolles’s work focuses on violent death and its aftermath, which she expresses in tough photographs and installations that often involve material residue from murder sites. She knew the Walmart for having often shopped there: Though based in Madrid, Spain, she has worked for many years in Ciudad Juárez, just across the border from El Paso, and much of her art responds to the borderland’s cartel wars, trafficking and gender violence.

Walmart stopped selling certain classes of ammunition after the massacre, but not all, so Ms. Margolles purchased a box of Winchester 12-gauge shells. Her large-format photograph of the shells is part of her spare but powerful new exhibition, “El asesinato cambia el mundo / Assassination changes the world,” at James Cohan gallery, in TriBeCa. Bright red with shiny metal ends, they are jumbled on a black surface in a pile that reminded me of a human heart with its valves and sinews. This ability to make visceral the ordinary tools and circumstances of murder is a hallmark of Ms. Margolles’s work.

The box of 25 shells cost $5.48, plus tax. Ms. Margolles paid cash. The original receipt is on view next to the image. It will fade during the show’s run, as receipts do, but you can take away your own reproduction, enlarged to poster size, from a stack at the gallery entrance. (When I photographed the stack, my phone invited me to scan the QR code for Walmart coupons.)