When immigration agents stopped Luis Mayancela's car outside a Lowe's hardware store in Monroeville on a frigid January morning, two men bolted from the vehicle. One escaped the officers after he ran across Route 22 and leapt down an embankment. Another was taken into custody. A third person in the vehicle, 22-year-old Mayancela, stayed behind - thinking he was safe from arrest after spending years and tens of thousands of dollars to ensure he was in the country legally.