A lawyer for the teacher said that on the day of the shooting, concerned teachers and employees warned administrators three times that the boy had a gun on him and was threatening other students.

California is still reeling from an earlier attack on a Lunar New Year celebration in Monterey Park that killed 11 and cast a shadow over an important holiday for many Asian-American communities.

The death toll rose to 11 on Monday after one of the 10 who were wounded died.

He paid four men to shoot at the homes of two county commissioners and two state legislators, police say.

Michigan was an early adopter in making terrorism a state-level felony and has among the most robust laws of the 34 states and District of Columbia that prosecute terrorism at the state level.