S8·E13 Loophole

Stabler ends out being out of commission after a perpetrator high on PCP throws him through a window at the station, so Benson teams up with Munch and Tutuola to investigate a mysterious packet of photos. The photographs lead them to both a suspected child pornographer and a junkie burgler, but after Benson takes ill during the investigation, the team realises that there is more than child pornography at stake as their investigation soon reveals that Seth Millstead wasn't into little boys at all, but had been using the tenants of the apartment building in an experiment for a new pesticide.