And check them frequently for tampering.
Get your neighbors and the PD together to form a Neighborhood Watch.
Put crunchy gravel under all windows. Go to the local nursery and get some prickly or razor sharp plants to guard the points of entry. Make sure all your windows stay locked and alarmed. You can get cheap window alarms at Dollar Tree. DO random weapon checks of the residents. You cannot over stress the importance of being armed for the time being. With the size team you've seen, you need a HIGH CAPACITY magazine in whatever you're going to use, be it handgun, shotgun or rifle. Be prepared to expend a considerable amount of ammo. Expect to experience multiple breeching attempts that will cut off your escape route.