Stopping break ins?

[Jon Klaus]

What are some ways to prevent break-ins, theft, and vandalism to vacant homes?

Alarm systems? Not keen on doing that (monitored)
for a short term. Lighting?

Someone stole copper out of one of mine this week. I thought there was less of that now with copper prices being down from the last couple of years. Fortunately, they left the AC alone. I filed a police (sherriff) report, but what else can I do to stop it from being repeated?