Numb3rs (2005)

S2E19 Dark Matter

Don and his team delve into a school shooting case. He uncovers that two students may have had a compelling motive. To gather more information, Charlie employs the school’s radio frequency identification system to monitor the shooters' movements within the hallways. When Charlie identifies an unusual pattern, the agents examine the evidence closely and uncover the involvement of a third individual who had previously gone unnoticed.