A mother who tossed her three young sons to their deaths in the San Francisco Bay was declared insane Wednesday by a judge, a ruling that means she will be sent to a mental hospital instead of prison.

The ruling came a day after a jury found Lashuan Harris, 24, guilty of second-degree murder, which carries a mandatory sentence of 15 years to life in prison.

The defense argued that Harris was schizophrenic and borderline mentally retarded and that she was convinced she was acting on orders from God when she threw the youngsters, ages 6, 2 and 16 months, into the water in 2005.

In a videotaped confession, Harris described struggling with two of the boys as she stripped them and plunged them into the bay in an area where tourists stroll along the waterfront. Her youngest child laughed, thinking it was a game.

One of the bodies was recovered. The others were never found.

Harris was put in a mental hospital six times between February 2004 and August 2005. On the day the children died, her mother warned a social worker that she would hurt the boys. But the social worker did not believe it, according to the defense.