Software, not Hardware.
So, I've thought that maybe he should take some nails and pound them through a board. We'll sharpen the nails to be like knife points. When the thieves jump through the window, they land on the boards and destroy their feet.
Is this legal?
A courtroom will eat someone alive if they do this.
One will hear over and over and over again:
-What a prudent person would do in this situation.
-Beyond a reasonable doubt.
Amongst other important sentences.
If you want to know what crimes are happening where you live-
Go sit in a courtroom.
If you want to know what the law defines and interprets -
Go sit in a courtroom.
If you want to know what one can and cannot do -
Go sit in a courtroom.
It does not make a tinker's damn what goes on in Texas, or Valley of the Zombies, what matters is, what is the law where you are when serious situations occur.
What matters is the law where you are, and how it is defined , interpreted, and sentencing.
Boards on a window are fine, these are
what a prudent person would do in this situation , while they wait on iron bars to be installed.
Preventive steps, layered defense with lighting, dawg, alarms, boarded window, iron bars are fine, and if someone where to breech these , then the person caught, would have to have his attorney
prove beyond a reasonable doubt as to how they got in, and the circumstances of when caught.
You go past legal, and you will then be the criminal.
This is Strategy & Tactics.
We use Software first, and always, even with Hardware.
Carl's post above is a good one.
One thing to mention, since he mentioned iron bars is while these are designed to keep someone out, one needs to consider someone needing out.
i.e. Fire.
Persons have to be able to exit, whatever they install to discourage, or slow down bad guys getting in.
One more time-
If one is busted into, they will be busted into again.
Your stuff is
sold before stole.
Bad guys not only wait for insurance replacement, to hit again, they also take inventory of what else they can "sell before stealing" when they are inside.
They also take pictures now, where they used to just take, calendars , day planners, address books and other items with personal information. With cell phones, just take a picture of the information they run across.
i.e.
-Calendar says Dental appointment at such-n-such time.
-Sister is going on vacation, and with address book, they have another easy mark.
-Work schedules with pay periods marked on a calendar.
Don't look like prey, think like a criminal.
Just don't become a criminal by being cute with measures installed and taken .
A jury of your peers, does not mean 12 persons exactly like yourself.