The Golden Police Department and Joint Terrorism Task Force were investigating a series of threatening emails sent to a member of the Islamic Center of Golden.
The emails came from an individual known to the member of the mosque, according a press release from the police department.
On Tuesday, the Council on American-Islamic Relations called for stepped-up protection of the mosque which is located on 19th Street near Jackson Street.
"A member of the mosque recently received an email from a person he had invited to the facility to learn more about Islam," the CAIR said in a press release.
"Because of the language and tone used in the email, we urge local police to step up security measures in the area of the mosque, particularly during activities associated with the upcoming Ramadan fast," said CAIR National Communications Director Ibrahim Hooper.
The group said the person mentioned using a gun, knife and other weapons to kill. The group released a small portion of the alleged email, which stated in part:
"In my pockets I carry two extra magazines~ even so I would run out of bullets before you ran out of Muslims. This is why I carry two knives and a collapsible baton as well."
“The Islamic Center of Golden is an institution dedicated to peace and harmony," said spokesman Qusair Mohamedbhai. “These types of ugly threats of violence and mass shooting against such an institution, effects it at its core."
Police officers have contacted the individual and conducted an interview, according to the Golden Police Department.
The person has been told not to contact worshippers or come near the facility, according to the CAIR.
The worshippers have also been warned about the threats and have a photo of the person and his vehicle.
"The members of the Islamic Center of Golden are very strong and determined individuals . And they will not allow this type of threat from practicing their faith in the greatest country of all," said Mohamedbhai.