An Ossining neighborhood was in a virtual lockdown Monday as police searched for a robbery suspect. Police Chief Joseph Burton says a taxicab driver called at 8:30 a.m. to say he had been robbed. The driver also told police that he thought the suspect was armed. Police, believing the suspect was hiding in a building located at 42 Broadway, sealed off the neighborhood. Once police got inside the building, they found it was empty. Police are continuing their search for the suspect. Anyone with information is asked to call 941-4099.