The LA School Police don't have a single repeater site. They have multiple sites and use a voted/steered system so when the dispatcher replies to a unit in the field the signal is automatically "steered" to the transmitter associated with the "voted" receiver site that heard the unit the best. I don't remember all the hilltop transmitter/receiver sites but I know they have Oat, Lukens, Mt. Lee, and PV. I think there are more receive sites than transmit sites.
Anyway, how it works is, a unit in the valley transmits, the receive sites "vote" on the strongest/best signal (let's say it's Oat Mountain) and that's the site the dispatcher hears. When the dispatcher replies, it will be steered through Oat. If you're in Long Beach (let's say) you may not hear Oat as well as you would Palos Verdes (for instance). The signal is voted many times per second and may bounce between sites quite a bit. Depending on where the unit is, and where you are, and what site is being voted/steered, you may or may not hear all the traffic.
Hope that's clear enough and helps. Sorry I don't know anything about unit designations.
Rich