Episode 108 of "Without a Trace"
s05e14 Primed

The team searches for an up-and-coming young artist who secretly photographs and then paints strangers on the street who are experiencing intense personal moments. As Samantha and Elena survey Abby Horton's ransacked studio, they wonder if Abby could have fallen prey to someone who was outraged to discover that Abby had immortalized their private moment. The team soon learns from Lucas Blumenthal (Paige), Abby's patron, that Abby was recently confronted by an angry male subject of one of her paintings. As the agents attempt to locate this man and another man who was reportedly fighting with Abby in an alley on the day before her disappearance, they also try to identify the other potential suspects in her photographs.