Three members of a group linked to six killings, including of a U.S. border patrol agent, were arrested in Western Maryland.

The "Zizian" group, which has roots in the San Francisco Bay Area, has been the focus of a multistate probe as investigators allege members are tied to a half-dozen killings in three states.

Three people were arrested in connection with a series of homicides in California and Pennsylvania as well as the shooting death earlier this year in Vermont of a U.S. border patrol agent.