YMMV / Law & Order: Special Victims Unit S3 E9 "Care"

• Diagnosed by the Audience: Glenn, the older foster brother of the murder victim, seems like he might be autistic. He is intellectually disabled, has self-injurious stims when stressed, doesn't make eye contact, and has a special interest in the Sword Quest video game (which turns out to help the detectives figure out that, like the final boss in the game, the real perp is female). But an actual diagnosis is never given. (There is some suggestion that it may be trauma-induced rather than a genetic disorder like autism.)
• The Woobie: Glenn is a sweet-natured Gentle Giant who was sexually abused when he was a toddler, and is now bullied as a teen for his intellectual disability. He lives under an abusive foster mom who everyone sees a complete saint. He turned to fantasy for comfort and tried to be a good big brother to the three girls who were also fostered in his house. When his foster mother beat one of the girls to death, he tried in vain to save her, only for his foster mother to try and let him take the blame. In the end, he's able to find the courage to stand up his abuser and make sure everyone knows what a monster she is, and his actions allow the other two girls to be given back to their mother, but he ends up back in the foster system.