Our investigations unit consists of five investigators and one sergeant. They investigate crimes that occur on or around our San Diego Unified School sites in accordance with the San Diego Police and San Diego Unified School Police Memorandum of Understanding (MOU) Although investigators normally work in plain clothes, when they are in police uniform, you can distinguish them by the two stripes on their sleeves. Our business hours are Monday-Friday from 7 a.m. to 5 p.m., but our investigators are subject to be called out 24 hours a day. If you would like to contact our Police Detective Sergeant, Alfonso Contreras, he can be reaches by email at acontreras@sandi.net or by phone at 619 725-7000.