A man facing charges in an April shooting at an accounting firm that left a receptionist dead and two managing partners wounded has been accused of trying to kill a sheriff's deputy.

The Detroit News reports Anthony LaCalamita III tried to stab an Oakland County deputy Saturday with a sharpened toothbrush at the county jail. He was arraigned Monday on assault with intent to murder.

The sheriff doesn't know what provoked the attack.

Messages were left Tuesday by The Associated Press with a lawyer for LaCalamita.

LaCalamita is charged with first-degree murder in the shotgun slaying of 63-year-old Madeline Kafoury and assault with intent to kill in the shootings of Paul Riva and Alan Steinberg at the Troy accounting firm.