Masked thieves who held up a Garda Armored Car Service facility in southwest Santa Rosa made their move as one of the company's armored vehicles pulled into the low, nondescript building late Thursday night, police said Friday.
Authorities said at least two gunmen made their way inside and quickly overtook two employees, who were "disarmed, tied up, and forced to cooperate with the suspects while being held at gunpoint," police Sgt. Steve Fraga said.
The gunmen robbed the company of an undisclosed amount of cash before leaving, closing a steel door behind them as they fled.
No suspects had been arrested by Friday afternoon.
Neither police nor Garda company officials would comment on the amount of money taken. But Garda company officials offered a $100,000 reward for information leading to the arrest of the robbers.
Beyond a broad outline of the 10:45 p.m. heist, police closely safeguarded details of the incident, including whether investigators suspect an inside job.
"It's a very significant loss," Fraga said. "We're reluctant to give details because the only people who are going to know are the people who planned it."
Detectives and Garda staff were taking steps to determine if company staff were involved in the crime, Fraga said.
Detectives also were examining surveillance video for leads.
The robbery came to light when one of the two victims called 911 to report that a robbery had just occurred and they were inside the Northpoint Parkway building, an operational hub used by the international, Montreal-based company.