You were of a victim of a crime regardless of the doors being locked or not.
I must make a very strong recommendation here. Do not leave valuables in your vehicle. Every day of every week we make reports of thefts from vehicles and every day of every week we are finding that items of value were left in the car. CD's, golf clubs, GPS systems, electronics, laptop computers, money, purse, wallet, camera's, tools, sun glasses, ID's, books, backpacks, I could go on forever. Lock your doors and removes all items.