The storyline involves a serial killer whose signature includes a specific action involving paper, leading to intense scenes with Dr. Melinda Warner and FBI Agent Lauren Cooper (played by Erika Christensen).
The Law & Order: Special Victims Unit episode features a significant plot point involving forensic evidence, specifically a document. [S9E12] Signature
Based on your query, the key paper-related element in this episode is: The storyline involves a serial killer whose signature