My question involves landlord-tenant law in the State of: CA

The situation:

Lived in a place with 5 total people (all friends) last year with a landlord who was really lazy and unreliable. Moved out a couple months ago when I realized I had never gotten my deposit. I called the landlord and he said that he had given the FULL portion of the deposit (5 people * $600) to the one guy who then took off with it. Is the landlord ultimately responsible/liable for our portions of the deposit? All 5 names were signed on the lease, and we each individually paid our own share of the deposit. I cannot remember if/what the lease said about the deposit being paid back, but I have to think that the landlord is responsible for giving each individual their respective portion of the deposit back.

Appreciate any help you can provide me with the situation.