DHCP not working properly on juniper

DHCP is not working very well for my Juniper SRX or maybe someone needs to point me in the right direction

dhcp {
            pool 10.10.0.0/16 {
                address-range low 10.10.1.1 high 10.10.255.254;
                maximum-lease-time 604800;
                router {
                    10.10.0.1;
                }
            }
}

but the problem is i have a device previosuly using dhcp get an address 10.10.1.24 and then now i want to set that ip as static ip for another device, so i shut off the device currently using that address and then set it as static ip for another device. 

The problem is when i start back the other device that first had that ip address via dhcp, it uses that same ip again because of the lease time i guess, but shouldn't dhcp server re-assign another ip since the first ip is now being used statically?

How can i have dhcp server behave like a dhcp server and re-assign ip addresses if they are being used for whatever reason. It need s to re-assign and that is the problem juniper srx dhcp can't do.

PLEASE HELP!

Thanks!!!