S9 E18: Rabid

The case was a man was torturing/incubating his victims by infecting them with rabies one after the other. When he was found, Derek and Spencer chased after him while JJ helped the victim, an about 25 y/o man. Derek tackled the UnSub, but had gotten electrocuted in the process. They were fighting, it was a whole thing. Spencer also got a small cut on his forehead.

Now, Rossi was with the family of the last infected victim, a woman, telling them the news of her death. Derek was talking with Spencer before you walked up to them.