Other mistake: When Hotch, Morgan and JJ review the footage from the first murder, they are able to zoom extremely close on the victim's hand. Why don't they do the same with the car license plate as the killer leaves? (00:21:45)
Other mistake: The age of the deceased Raymond Leu (35) shown in a death certificate doesn't match up based on year of birth (1948) and year of death (2014).
Chosen answer: Back in Target Rich, a hitman named Giuseppe Montolo dies whilst being interrogated by Derek. The men who abducted Derek were hired by his father, Chazz, who seems to blame Derek for his son's death. It's explained further in A Beautiful Disaster.
Annabel Keeley