In the wake of the deadly anti-Semitic attack at the Tree of Life synagogue in Pittsburgh, ProPublica and Frontline present a new investigation into white supremacist groups in America — in particular, a neo-Nazi group, Atomwaffen Division, that has actively recruited inside the U.S. military.

Continuing ProPublica and Frontline’s reporting on violent white supremacists in the U.S. (which has helped lead to multiple arrests), this joint investigation documents the group’s acts of violence and asks how aggressively civilian and military authorities are taking the group’s terrorist objectives and how it gained strength after the 2017 Charlottesville rally. (Watch the first documentary in this series, August 2018’s “Documenting Hate: Charlottesville,” online.)

Tune into the premiere on PBS on Nov. 20 at 9 p.m. Eastern, 8 p.m. Central and online at pbs.org/frontline.