That, and choosing to live in a neighborhood where warrants of any kind are rarely served. Outside video surveillance also helps. If you see three or four guys in plain black clothing, armed with a variety of weapons, and just wearing ball caps with "POLICE" on them, chances are they AREN'T POLICE.
Real Police like to dress up in gear that's well marked, wear body armor, and are armed with standard police weapons, not "Tec-9's, AK-47's, etc".
A nice strong door with multiple deadbolts and a reinforced frame keep intruders out so a call to 911 can be made to verify it's a real "raid".
Of course the risk is far less if you don't live among those who are most likely to be subjected to armed warrant service.
Police do not always wear marked clothing. Take the Auburn police for example.
Several months back I was driving south bound on A street. Suddenly their seems to be blue lights everywhere. I could see some marked cars in various locations.
Then some unmarked cars arrived and everybody, uniformed and plain clothes, suddenly left their vehicles (still running, doors open, in the dark) in the middle of the road and ran off in about 5 different directions.
There was no communication with the Citizens trying to get home. We just sat there wondering what the hell was happening.
Some police went into the rail yard and others went into the neighborhood.
The plain clothes were wearing black plate carriers without any markings and carrying AR15's.
This was shortly after some of the domestic "ISIS" attacks this past year.
Of course this is the same PD that I saw detaining a kid in the Fred Meyer parking lot for selling weed. They felt it necessary to send two officers wearing plate carriers and AR's.
