The FBI says it has discovered a “target list” compiled by the gunman in a California mass shooting that listed nationwide religious institutions, federal buildings, courthouses and both major political parties.

The list has prompted the FBI to open a domestic terrorism investigation into the case in which gunman Santino William Legan shot and killed three people, including two children, on July 28 at the Gilroy Garlic Festival. The festival was also listed as a target.

John Bennett, the FBI’s agent in charge in San Francisco, says authorities still have not determined a motive and Legan appeared to be interested in conflicting ideologies.

A separate shooting that killed 22 people at a crowded El Paso, Texas, store over the weekend is also being handled as a domestic terrorism case.