The doctor is charged with three felony counts of poisoning and one felony count of domestic battery with injury, the Orange County District Attorney's Office said in a statement.
The victims of the mass shooting have been identified as Evelyn Dieckhaus, 9, Hallie Scruggs, 9, William Kinney, 9, Cynthia Peak, 61, Katherine Koonce, 60, and Mike Hill, 61.