NEW YORK — For years, it was unclear whether the schizophrenic killer of a Manhattan psychotherapist would ever be stable enough to be tried in the meat-cleaver attack he acknowledges he committed.
But as David Tarloff’s murder trial began Monday, prosecutors argued his mental illness is no defense for a methodically planned robbery that turned deadly while the defense told a jury Tarloff believed God had approved of a scheme so insane it shows he didn’t understand the horror of what he was doing.
Defense attorney Frederick Sosinsky described Tarloff’s plan in his opening statement: Strong-arm psychologist Kathryn Faughey’s officemate into giving up an ATM code, withdraw tens of thousands of dollars and spirit his gravely ill mother away to Hawaii.
‘‘This is absolutely crazy, insane, delusional thinking,’’ Sosinsky said.
Tarloff, who had become fixated on the idea nursing homes and hospitals were mistreating his mother, was so psychotic, Sosinsky said, that ‘‘he thought he was doing not wrong, but right.’’
In the carnage he caused in the Upper East Side office in February 2008, Tarloff, now 44, killed Faughey and wounded psychiatrist Kent Schinbach.