Residents watch the police checkpoint in D.C.'s Trinidad neighborhood on Saturday, June 7, 2008. (AP Photo/Jose Luis Magana) We balked at the initial news that the Metropolitan Police Department planned to throw up barriers and checkpoints in certain D.C. neighborhoods experiencing excessive violent crime. Later, when we learned the details of the first case, the week-long checkpoint that was established in Trinidad, the MPD's plan appeared to be both constitutionally dubious and potentially not......