REDWOOD CITY – Four men have been arrested and more than two dozen firearms have been seized as part of a gun-trafficking investigation in San Mateo County, authorities said.

The investigation began in October and involved the San Mateo County Sheriff’s Office; the Bureau of Alcohol, Tobacco, Firearms and Explosives; the San Francisco Police Department; and the San Francisco Drug Enforcement Administration Metro Task Force, Lt. Michael Leishman said in a news release Friday.

Leishman said the investigation identified and targeted people involved in the trafficking of guns from Arizona to California and the illegal sales of those firearms throughout San Mateo County.

During the investigation, agents purchased various types of guns, including privately made firearms, also known as ghost guns, as well as serialized firearms and automatic rifles, Leishman said.

On Thursday, authorities served arrest and search warrants in San Mateo County and Oakland. Leishman said authorities seized 15 firearms, thousands of rounds of ammunition, a suppressor attachment, automatic pistols, high-capacity magazines and a 3D printer.

The investigation, which is ongoing, has resulted in the seizure of 30 firearms and the arrest of four men, two of whom were taken into federal custody, Leishman said.

Anyone with information related to the investigation can contact Leishman at mjleishman@smcgov.org.

Source: www.mercurynews.com