(CNN) -- Police seized a Maryland man who called himself a "joker" and threatened a supervisor, the latest of several arrests over threats after last week's massacre in Colorado.
Police in the Maryland counties of Prince George's and Anne Arundel acted swiftly on the threat and the use of the word "joker." The Joker is the nemesis of the comic character Batman and a character in the film the "Dark Knight Rises."
James Holmes -- who last week shot up a movie theater in Aurora, Colorado, showing the film -- identified himself to police afterward as "the Joker." He has been arrested in the massacre, in which at least 12 people were killed and dozens more wounded.
"It was related to patrol officers that at that time that an individual who was in the process of being fired was involved in two separate conversations with his supervisor. Both of those times and both of those telephone conversations he made significant threats to coming back and harming people at the business," Prince George's County Police Chief Mark Magaw said Friday. "In fact, he said 'I'm a joker and I'm gonna load my guns and blow everyone up.'"
Magaw said that in light of the Aurora incident, "it's important (for) the community to know that we take all threats seriously and if you're going to make a threat, we will take action."
Police say the suspect, who owns firearms, is having a mental evaluation. He was taken into custody early Friday morning, officials said.
"We believe this was a significant threat based on some of the mental issues this individual has, the weapon capability he had (and) what he said to the employees at Pitney Bowes," Magaw said, referring to the business involved.
Pitney Bowes issued a brief statement Friday afternoon saying the man was an employee of a subcontractor for the company and "has not been on any Pitney Bowes property in more than four months."