Scared to Go Back

I'm afraid the scum bags who stole our stuff returned and stole everything else.  We'll find out shortly.  I've been racking my brains trying to come up with an acceptable theft deterrent that wouldn't injure my family or land me in jail.  So I think I have a plan:

Part of the middle ledge section has a narrow three foot passage.  I will construct a lockable barricade at that narrow point and place any lockable valuables beyond it.  I will also attach bowling balls to items with padlocks. I'm encouraged these seems doable.