A white-bearded ISIS militant who presided over the killings of dozens of gay men and others who ran afoul of the so-called "caliphate" was captured in the Iraqi city of Mosul last week, according to reports.
Abu Omer was arrested after locals in Mosul tipped security forces off to his hideout in the city, the Iran-based AhlulBayt News Agency (ANBA) reported, citing Iraqi media outlets.
Abu Omer was a prominent presence in several sick videos of ISIS executions, in which homosexuals were thrown off buildings and others beheaded and stoned to death for minor offenses such as blasphemy.
In one video, apparently from March 2015, a man who appears to be Omer reads off a list of charges against three men before they are publicly beheaded.
Another photo appears to show Omer inspecting a pile of rocks before a public stoning. Now, this most feared ISIS executioner could be executed himself.
According to a Human Rights Watch report released last month, approximately 20,000 people are being held across Iraq on suspicion of ties to ISIS.
It is unclear how many Iraqis have been slaughtered by ISIS, which swept across the country in the summer of 2014 before gradually being pushed back by government forces supported by a U.S.-led coalition.
An Associated Press investigation has found at least 133 mass graves left behind by the defeated extremists, and only a handful have been exhumed. Estimates vary between 11,000 and 13,000 bodies in those graves, according to the AP tally.
The Associated Press contributed to this report.