RICHMOND, Va. (WRIC) — The history of two non-U.S. citizens accused of plotting an Independence Day mass shooting in Richmond is under the microscope, alongside the high-powered rifles and a handgun seized from the Southside home they rented.

Hours after the Richmond Police Chief shared initial details into their investigation Wednesday, a department spokesperson said the men who were charged in the conspiracy are from Guatemala.

Julio Alvarado-Dubon, 52, was arrested July 1 at the Columbia Street home he rented with Rolman Balacarcel, 38, according to the department after an officer in the Second Precinct received an anonymous tip from someone who overheard a conversation concerning Balacarcel.

A spokesperson for the department said the tip did not specify a specific location for the threat, but did mention: the Fourth of July, a shooting plan and Balacarcel. The spokesperson said the reason Dogwood Dell and The Diamond were areas of concern was due to the large number of people who attend annually.

Police Chief Gerald Smith said when officers arrived at the suspects’ home, Alvarado-Dubon opened the front door, revealing that a gun was in “plain sight.” A Spanish-speaking officer then asked Alvarado-Dubon if they could enter the house — he reportedly complied.

8News is told two AR-15 rifles, a 9-millimeter handgun and over 200 bullets were seized from Alvarado-Dubon’s bedroom.

Authorities seized two assault rifles, one handgun and more than 200 rounds of ammunition from a residence in the 3100 block of Columbia Street on July 1 after receiving a tip from someone who had overheard plans for a mass shooting in Richmond during the holiday. (Photo Courtesy of the Richmond Police Department)

Smith said that at the time officers searched the home, there was no probable cause to arrest Balacarcel, but officers kept him under surveillance, and he was arrested in Charlottesville on July 5.

“If he [Balacarcel] were to try any act of violence our officers would have acted swiftly beforehand. We were watching him very, very closely,” Smith said.

Both suspects were charged with possession of a firearm by an unlawful alien, and Smith said more charges could arise.

The circumstances of when the pair entered the United States is unknown, as is their connection to Central Virginia. 8News awaits a response from the US Department of Homeland Security.

“We know what their intent is but we don’t know their motive,” Smith said.

Richmond police acknowledged 8News’ request for information about the possible registered owner or owners of the firearms seized, and how the suspects acquired them.

The US Bureau of Alcohol, Tobacco, Firearms and Explosives told 8News, that the organization is “prohibited under federal law from providing trace information to anyone other than law enforcement,” according to their chief of public affairs.

It’s unknown when Balacarcel will be in court next, but Alvarado-Dubon is due on August 1 for a bond appeal.

Correction: The spelling of Julio Alvarado-Dubon’s name has been updated. Previous versions of this story contained a misspelling provided to us by law enforcement.