The death toll in a Northern California shooting rampage rose to five on Wednesday after the authorities said they found the body of the gunman’s wife hidden under the floor of the couple’s house. The death toll, the authorities say, could have been much worse had an elementary school not ordered an immediate lockdown.

The gunman, identified by the Tehama County Sheriff’s Office as Kevin Janson Neal, killed his wife, shot neighbors, attacked an elementary school and drove through the small rural community, firing at motorists early on Tuesday morning. He killed a total of five people and injured 10, including seven children, before he was killed by the police. One child who was shot at the school was in critical condition on Wednesday; the other children suffered less serious injuries from flying debris.

The shooting rampage lasted around 25 minutes and took place at different locations across the unincorporated community of Rancho Tehama Reserve, Phil Johnston, assistant sheriff of Tehama County, told reporters on Wednesday.

Mr. Johnston said investigators believed that the rampage started with the killing of Mr. Neal’s wife, possibly on Monday night. The police believe that Mr. Neal shot and killed his wife, cut a hole in the floor of their house and placed her body inside.