Do you own the land? There are townhouses that condominiums and townhouses that are fee simple where you own the land.
The tree is private property and he had no right to cut anything. Is the landlord willing to take action against him for property damage? It really bothers me that he didn't want his name on the police report even though it's very clear he was behind having them sent out. It really bothers me too that untruthful accusations are being made against you. I am concerned that you may need more proof to get the police to assist you. For defamation of character you need damages, such as the HOA fining you for violations. If it gets to the point and the HOA takes action against you based on this information you would have grounds for harassment.
I understand that this is extremely stressful and I have no doubt that he is targeting you.
If you catch him the act or get any neighbors to admit that he is behind the complaints you should absolutely file a complaint against him.
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