Linda Russo is found in a street near her home, strangled, as it turns out, with a triple green/white nylon rope. As Castle suspects, it's the slightly modified MO of serial killer 3KX, who stopped killing four years earlier. Her 'stalker', colleague Paul McCardle, has an alibi and was chased away from her apartment building by a bogus security guard, another 3KX specialty. With a second victim, the killing pattern is confirmed. Fingerprints on a name tag found in the second victim's apartment, leads to recently released ex-con Marcus Gates. He's found and arrested, with a confession, with information supplied by Jerry Tyson, his cell-mate while in prison.
—KGF Vissers