New players will often times attempt to kick experienced players for random killing or even accuse them of cheating. Most of us will nicely explain, that we killed them based on their movement.
None of us enjoys this mechanic. But with most servers being ranked, and unranked being a brand new addition to the game, most of us don't want to ignore the robbers if we see them. I always feel sorry if I movement kill people, but if I don't they might backstab me and blow me up.
So let me quickly share what I know.

Here's what I know about NPC movement:
- Every other update, the developer adds slight changes to movement, to discourage people from killing players based on movement without any mentions in the patch notes.
- There is an "old movement pattern" and the "new movement patterns"
- NPCs switch from the old to the new movement patterns randomly

Old movement pattern:
- NPCs will move from a POI to another POI. Those points of interest are placed in the level editor.
- They will take the shortest possible route, which means they walk in straight lines if possible, and if there's a corner, they will take the shortest possible route around corners.
- NPCs (sometimes) dodge each other with short side steps.
- If they don't, they sometimes walk into each other, awkwardly sliding around the other person.
- When turning around, NPCs can sometimes walk backwards while turning. I call it moonwalking.
- NPCs don't turn in the middle of the room with the old pattern

New movement pattern:
- NPCs can slowly walk in circles or half circles
- NPCs can sprint in very small circles (bug)
- NPCs can turn in the middle of the room or hallway (rare)

Here's two images showcasing the correct movement in green and the wrong movement in red around two specific corners. There are more possibilities, especially in the arcade example, where there's a POI behind me, but I didn't want it to be too chaotic.

Arcade:


New York:


Good luck trying to replicate the green lines.

A common mistake new players make, is staring at cops for too long.
Even though NPCs can sometimes do it, once the cop starts moving around you, you should definetely stop staring at him and walk away.
It's always good not to look directly at a cop with your crosshair dead center on him, but rather look at him out of the corner of your eye.

It might be a survivial instinct to look back at a cop after he started stalking you. Don't. The less you care about a cop behind you, the better your chances are of getting away.
After walking a straight line and stopping for 2-3 seconds, you can slowly turn your mouse at a consistent speed to look around.