Portland police believe they've solved a September stabbing at the Gateway Transit Center, arresting an 18-year-old man Thursday. The Gang Enforcement Team, assisted by the Beaverton Police Department, arrested Miguel Vargas in connection with a Sept. 23 stabbing of 19-year-old Christopher Shoop-Lockett on the MAX platform. Shoop-Lockett was stabbed nearly 20 times before his assailant fled the area. Gang detectives determined that the victim and suspect were from rival gangs. Vargas was booked into the Multnomah County Jail on attempted murder and second-degree assault charges. He remains held in lieu of $500,000 bail.