THE BRONX - NYPD officers make dozens of arrests each day, but civilians are being credited with making a collar in a Pelham robbery. Neighbors in a Pelham apartment building made a citizen's arrest last night after a suspect allegedly tried to assault and rob a teen. People living on the second floor of the building say they ran to help after hearing a woman's screams. Witnesses say the man was pretending to be a police officer when he started trying to beat the 16-year-old girl and force his way into her family's apartment. A group of neighbors say they tackled the suspect and pinned him up against a wall for 20 minutes until police arrived on the scene.A second suspect managed to escape, officials say.