Perfect

S4 E24: Police responding to a shooting find a dead teenager, who's filthy and appears to be homeless. She's also been shot and Detectives Benson (Mariska Hargitay) and Stabler (Christopher Meloni) are concerned that one of the cops shot her by mistake. Even though the bullet hit the teen, she was already dead. She is identified as Samantha Tassler, a black teenager from a well-to-do family outside of Philadelphia who disappeared almost a year ago. She is wearing an unusual necklace, of the infinity sign, and they trace the custom piece of jewelry to Dr. Garrett Lang (Gale Harold), who had multiple copies made. Dr. Lang is quite charming, and he runs a clinic that specializes in hormone replacement and perpetuating youth. Suspicious of Dr. Lang they sift through piles of his records, and in the process Detective Munch (Richard Belzer) discovers he owns an office building and three brownstones. It seems Dr. Lang applied for tax-exempt status for one of them, and they find out he claimed it as a charitable organization. The Detectives decide to check out the "Foundation for Knowledge Expansion".