In the crosshairs

The question presented: how do I tell if a person trying to enter my safe house is a looter, a raider or another survivor?

I will address this question in a number of points. I'll try to keep everything in some sort of order because I have a lot to say on the matter. This is a vital point which will effect many survivors as they face a situation they may not have prepared for properly. An entire protocol should be discussed with the group very shortly after a safe house is secured.

One clear indicator if a group approaching a safe house is friendly can be children, anyone with children at least gets a chance to explain themselves in my books. That being said children can also be used as a lure. All children can be deceiving and children raised in the wrong way can be more brutal than grown men (child soldiers are an example in real life and Carl in The Walking Dead is an example in zombie fiction.)

Also looking scared and generally running for their lives. Of course some people are amazing actors so this just gives the advantage of not looking like an enemy from the start. Also it is worth noting at this point that anyone in a dangerous enough situation will appear frightened and chaotic.

In general it's all about body language, something most men actually have a lot of issues with and thus it is important to have either a man who understands body language (an actor, a police officer, etc.) or a woman who is hardened enough to pull the trigger. Hate to stereotype but it's just the reality, women know people better but empathize more quickly. This may seem like a rather non-scientific way to determine something with as serious a nature as this but regardless it will be the defenders best indicator. It is thus imperative to develop a good sense of understanding body language; this skill will be useful from the moment of meeting your first other survivor until the end.

Thinking about this first question leads to a burst of potential situations. These situations come from the idea of asking a couple of questions: "Who wouldn't I shoot on sight?" "What would I do to make myself look less threatening?" "How do I see through the disguise?"

Who wouldn't I shoot on sight?
Well anyone who didn't look like a threat or I hadn't already had negative dealings with. And this even includes groups of men: I would hate to mow down some men or start a gunfight when it turns out they were just the men from a group near by who left their children and elderly to search for supplies. So for instance a group calmly walking in the middle of the street they could be a band of raiders OR they could be just a surviving party. Most people aren't expecting to have a sniper's cross hairs on them after the fall. Again that comes down to body language. Figure out who the leader is and what he looks/acts like, first impressions are a hard things to go off of but 9 times out of 10 they are right on the money for anyone with some skill in reading people. And the people who do look like threats are going to realize this really quickly and start trying to not look like a threat. Which makes our jobs as survivors a lot harder and leads to the second question.

What would I do to make myself look less threatening?
The answer is simple: anything and everything. There are some situations where it is a benefit to appear more threatening and to intimidate an enemy, group or even individual but for most situation if approaching a safe house the easiest way to be let in peacefully is to appear to be of no threat. And I for one would hate to be honestly looking for no trouble, but maybe just  meal and a place to sleep and be shot because I looked like a threat. Well having children helps as already mentioned. Keeping them safe is of course a great concern but letting them be seen shows that I have something to lose and to protect so I am not looking to be rash and violent. Leaving all weapons holstered also lowers the threat level by a great amount, this is an option not to be taken lightly. A way to make yourself appear less threatening while still being able to defend yourself instantly is to keep a sidearm in hand but not at the ready, keeping the arm outstretched and barrel pointed safely toward the ground is a clear indicator of no harm intended and while this may mean not getting the first shot off it will allow to react to any shots fired instantly.
Another option is to learn the art of the diving quick draw. This is an act which should be practised for hours until it can be completed in any area, on any terrain, with any pressures, to absolute perfection. If that is done this move can be a life safer. The act is simple in design but hard to complete. Throw your body in one direction, to one side or the other normally offers the best mix of changing position and arm movement. Diving forward is the lease expected motion but the least change of position which makes it easiest for the enemy to adjust their shots. It also requires the most arm movements to draw your weapon and bring it all the way up your torso and over your head to fire. Throwing your body back offer the least arm movement and thus the quickest firing position, simply draw, point and fire. Again going backward does not make the enemy have to do much to adjust their aim. Second, as the body moves the arms must be moving to quick draw your sidearm. If you have ammo to spare a shot can be fired as soon as the weapon is out of the holster, this will do two things: surprise the enemy who will already be surprised by the bold and strange maneuver, and use recoil to move your arm up to firing position even quicker. This first shot would be while you are still in the air and has almost no chance of doing damage, the real firing will be done once you hit the ground. Firing position and aiming should be done during the final part of the dive so the second shot and more if needed can be taken upon contact with the ground. Note that being on the ground does not cause as many issues in a gunfight as many people seem to believe. Not only does the target become unfamiliar and smaller but also allows the most stable firing position and allows for easy movement while maintaining that stable position i.e. rolling. While this does throw off aim it is the quickest way to move from stable position to stable position while covering some ground. And especially in an area with no cover making yourself a small and foreign target will be your greatest asset.
That may seem to have little to do with being less threatening but being confidant in your ability to defend yourself even with your weapon holstered will present you as calm and poised showing that you have nothing to hide. Some one who is uncomfortable and insecure will appear as such and could be taken as being dishonest or looking for an opening to attack. Remember that a confident warrior does not actively look for openings, he simply notices them or he creates them the moment they are needed.
Clothing can also be a simple of threat. A person in leather straps, spikes, and punk hair simply looks more of a threat then a person in jeans, a sweater and uncombed short hair looks. This is again stereotyping but when it comes to survival in a world which has lost it's current society every little thing will be a matter of survival. Even more so a group of people dressed in a pattern or a common "uniform" will appear much more threatening then a group who are all dressed differently. While dressing the way you want is every person's right it is fair to note that to the true survivor dressing in a manner which will give a better chance of not being taken as a threat by other survivors is almost as important as dressing to protect from bites.

And of course the final question being how do I see through the disguise?
Not an easy question to answer but it is the true rout of the first question. I have not discovered a formula to do this. I have no set 100% way to determine. Rest assured I am searching for one. But for now I would say the best way is through feeling. Feeling is a weird thing to go off of but it is often all we will have as survivors. Often the path will split and with no time for to work out a decision one must trust their feelings and make a choice. Seeing through a disguise is much the same. Sometimes it will be obvious, a person with shifty eyes, the followers being uncomfortable while the leader is comfortable or the opposite, hands held near weapons at all times, distrust and lies weaved in their words. But other times it will be harder to determine such as if the leader is too smooth. What is too smooth? If he has all the answers without actually giving any answers. When the followers look to him in fear. If he makes statements about all the things you can do for each other. Key words and phrases might be "imagine" "together" "peace of mind" "chance to succeed" "common sense" "security." Now note just because someone uses these phrases does not mean they are automatically too smooth, the leader is possibly just well spoken and thought out but these words can be flags to start looking for others. Another flag will be speaking down to the followers and inspiring them, or speaking to your group and trying to turn them to his side. Another flag might be if the leader already has a well worded list of things he can offer you and how you would both benefit from giving him help. Of course too smooth is partly a feeling and partly an understanding of what true leadership versus blind/terrified followers is. Feeling is something we do everyday when we meet new people, we just have to start tuning into those senses and realize when something is off about a person. This is not a 100% science but it is can be the best a survivor has to go off of after the fall. Gut feelings tend to be right, and following them may safe you from the feeling of a knife in the gut.

Stay vigilant, may the infection never reach you, and those close to you have the resolve to do what is needed should you be so unfortunate, Mike D.