O'Toole is a human man, and a rookie in the Special Investigation department of the Chicago Police Department. He first appeared in Blood Rites.
Described as large and brawny. 
O'Toole is Micky Malone's nephew. Karrin Murphy tells Harry he'd jump through hoops for him if Harry asked him too. 
In Blood Rites, Karrin beats him at in practice at Dough Joe’s Hurricane Gym. 
- ↑ 1.0 1.1 1.2 Blood Rites, ch. 6