Rossall, if this is not too audacious of a plan for you...
Purchase one of those 50,000 - 200,000 lumen ultra-powerful flashlights. They are better than tranquilizers or tear gas in that it is COMPLETELY legal AND does not cause permanent harm. Also, buy a can of bear spray. The flashlights are rather expensive though; the MS18 is 700 dollars. After purchasing one online, you can opt for it to be delivered directly to your apartment.
The Imalent MS32 delivers 200k lumens. This will be your best choice.
Alternatively, you can opt for the MS18, for 100k lumens, should the former's price tag be formidable.
For a complete catalog of Imalent's products, you can either go to their website or their Amazon equivalent, duly listed here:
Company: https://www.imalentstore.com/
Amazon: https://www.amazon.com/imalent-flashlig ... flashlight
Here's what you should do, if you do choose to go with this plan:
1. Wait for the tenant to get close enough to you
2. Take the flashlight out of your purse/side-pack.
3. Aim it at said person's face
4. Turn it on, and let the full power of the Sun descend upon his face and the entire neighborhood.
5. After a few seconds, turn it off. Wait for him to regain his senses.
6. The target transitions into a hostile state. Take out the can of bear spray, and apply the solution liberally upon his facial features, preferably from beyond melee range.
7. Repeat steps 1 to 6, for as many times as is necessary, until target verbally promises to cease entering your neighborhood,
8. Profit.
This is completely legal, and carries no risk of you being tangled in courtroom battles. The combo of extreme visual disorientation + chemical irritation, should impose enough of an internal behavioral blockade upon the applied person if done correctly, as to deter the undesirable behavior indefinitely.
You can carry a short tree branch, or a suitable rod-shaped object within your dwelling, with you if you are worried the tenant might be too tough of an opponent for you. This is my sincere advice, and is PRECISELY what I would do in your situation if I had the funds to put this plan into motion. And now, I present this plan to you.
I wish you the best in all your endeavours, Mr. Rossall.
_________________
//Words are the supreme objects; they are minded things.
//In such seconds of decision entire futures are made.