It seems that real estate is a second income for lots of Officers that I know. Generally it is not in the form of showing homes to potential buyers, but buying them and renting out. Several guys in El Paso make more money doing that than being full time officers. They bought duplexes and rent them to incoming officers.
A bit of advice, coming into LE requires 100% dedication in order to learn the job, and more importantly to stay alive. Those officers that I mentioned above didn't do anything except their LE job for the first 3-4 years. You need that much time to really break into the job, culture, and tricks of the trade. Do one or the other, and do it well. Once you have time and experience under your belt, you might want to get back into real estate. Just my $0.02, never the gospel.
"Kid, I've sat on the department ****ter longer than you've been a cop." (CatDoc to Chevy SS, the single greatest post ever on RP!)
Moon Pies and RC Cola make me happy