Maxpower,
You're ignoring the basis for my suspicions.
Taking photos of the front of the house wouldn't concern me unduly - real estate agents and appraisers are a common sight, as are landscapers, pool maintenance guys, HVAC, plumbers, electricians, et al.
Rattling windows and door knobs, jumping walls and gates, or skulking/prowling would DEFINITELY put me on my guard, whether you were armed or not.
Also, an armed stranger who is approaching/addressing me (as opposed to doing his job/minding his own business) would also put me on guard, especially one that exhibited the above behavior.
How would you react if it happened on your street?
mbogo
I'm not sure how you derived from my original post that I'm doing any of these things.
When I arrive at one of the addresses I've been tasked to check out, here's what I do:
1. Take a picture of the number plate on the house for address verification.
2. Take a picture of the front of the house from the street.
3. Check gas and electric meters to see if service is on or off. Take a picture of the gas meter valve for verification.
4a. If utilities are on, I check the front door for posted notices that the house has been confirmed vacant by the lender. If no notices are posted, I take a picture of the front door and pictures down the street in both directions for an overall view of the neighborhood. I jot down some notes and move on to the next house.
4b. If utilities are off, I'll again look for notices on the front door. If they are there, then I'm certain the house is vacant. I try my keys to get inside. If they work, great. If they don't, I'll take pictures of the interior through windows. Perhaps this is your definition of skulking/prowling. At no time am I trying to force my way inside and at no time do I jump over locked fences or walls.
I understand you being on guard while being approached by a stranger. It's certainly the prudent thing to do. I'll keep a standoff distance of about 5 yards when I initially attempt to start a conversation with a neighbor. Usually it's "Excuse me sir/ma'am, may I ask you a question about this house across the street." From there I'll explain my purpose for being there and see what information the neighbor is willing to share about the house.
The purpose of trying to engage the neighbors is two-fold. One, most that I've talked to love to gossip and they usually have some pertinent information to help value the house. Two is to show them that I am being right out in the open about what I'm doing and why I'm there in an attempt to show I have no nefarious notions in mind. Some watch while I'm there to be sure, and what they see is what I described above. If I get inside the house, they'll see me go in with nothing but a camera in my hand and they'll see me come out with nothing but a camera in my hand 3-5 minutes later.