Dr. Norman Miller testified Thursday in Abuelazam's trial in the 2010 stabbing death of Arnold Minor, The Flint Journal reported.
"Because of major mental illness, paranoid schizophrenia, he did it," Miller told the court. "These evil forces just express themselves through Mr. Abuelazam. There wasn't any question about whether what he was doing was right or wrong."
Miller said he evaluated Abuelazam twice in 2011, and also cited a history of mental health problems. Abuelazam, who attempted suicide in 1997, stabbed a friend in 2009, after which an Israeli psychologist diagnosed him as "psychotic."
"The delusions, not Mr. Abuelazam, would want to hurt them," Miller said. "His intent was not to kill anyone. He would stab them once or twice and then leave. He would not stay to finish them off.
Prosecutor David Leyton said last week he had three witnesses that say Abuelazam is sane, and thereby criminally responsible for the stabbings.
Abuelazam is accused of killing five people and injuring nine, however, he is only on trial for Minor's killing, the newspaper said.