One week after Colorado's movie theater shooting, Maryland cops have foiled what they believe could have been another massacre.
Law enforcement sources tell ABC News that a man from Crofton, Md., is under arrest for allegedly making threats against an employer and co-workers.
The suspect had more than 20 firearms at his residence, including semi-automatic rifles, shotguns and handguns, law enforcement sources said. Sources also said he had more than 1,000 rounds of ammunition.
The man was reportedly facing termination from his job in Prince George's County, according to ABC News' Maryland affiliate WJLA.
The Prince George Police Department declined to comment, but said they will be sharing more information at a 1 p.m. news conference.
On July 20, shooting suspect James Holmes allegedly opened fire in an Aurora, Colo., movie theater during a midnight showing of the new Batman movie, "The Dark Knight Rises." Twelve people were killed and 58 were wounded.