Joshua Cummings is pictured in this booking photo. Denver Police Department/Handout via REUTERS

February 3, 2017

DENVER (Reuters) – A Denver mosque warned the U.S. Department of Homeland Security a Muslim convert was radicalized more than a month before he was arrested in the shooting death of a security guard, officials said on Thursday.

Joshua Cummings, 37, was taken into custody in Denver on Tuesday on suspicion of fatally shooting Scott Von Lanken, a transportation agency security guard and former pastor, that night, police said.

Detectives are investigating whether Von Lanken was targeted because he wore a uniform similar to those worn by police officers,