Monica Sementilli, 45, was arrested Wednesday and booked on suspicion of murder. She is being held without bail.
Police are releasing few details about her arrest, including discussing to what extent it may have been in connection with her husband's death. A press conference has been scheduled for Friday.
Fabio Sementilli, 49, was found stabbed and beaten on the patio of his home on Queen Victoria Road on Jan. 23.
Sementilli, had worked for decades as a trendsetting hair stylist and served as vice president of education for the beauty products giant Coty Inc.