A Virginia man was arrested at a church after allegedly being found inside with a loaded semi-automatic pistol with an additional magazine, a folding knife and a folding "credit card"-style knife, according to police.
Fairfax County police arrested 35-year-old Rui Jiang after becoming tipped off by a Maryland woman who called police in Ann Arundel County, Maryland, to report that Jiang allegedly made suspicious posts that included "vague threats" on Instagram, according to the police report.
Fairfax Police Chief Kevin Davis said, "This was a thwarted diabolical plot to kill churchgoers in Haymarket, Virginia, and local law enforcement stopped it."
MORE: 10 dead, 10 wounded in mass shooting in Monterey Park, California, with suspect found deadAnne Arundel police alerted authorities in Fairfax County, Virginia, that Jiang allegedly made threats against the Park Valley Church in Haymarket.
"In the postings, vague threats of violence were made, some of which included images of a location later determined to be Park Valley Church," Prince William County police said.
Police were able to quickly locate Jiang's assumed residence in Falls Church, Virginia, but found he wasn't home, according to the police report.
As the investigation continued, Fairfax County police contacted Prince William County police and an off-duty, uniformed Prince William County police officer who was working an assignment at the Park Valley Church located the car outside, police said.
Police at the church identified a suspicious person who they later identified as Jiang. He was detained after entering the building through a separate door.
No one was injured during the incident however, Fairfax County police say they later discovered Jiang's "disturbing" "kill manifesto," at his home. However, police did not describe what was found in the alleged document.
MORE: 12 shot in Baton Rouge nightclub, police sayJiang was charged with threats of bodily harm and carrying a dangerous weapon in a place of religious worship.
Jiang's bond hearing is scheduled for Wednesday morning. It wasn't immediately clear if he had an attorney who could comment.
Prince William County police have asked anyone with information leading up to this incident, please call 703-792-7000.