Keyloggers>how do I detect? I had a freaky landlord in Townsend,TN who knew ALL my business?

He knew all about my life-things I typed in emails. I heard he did the same to his other tenants, and even had cameras in the unit 119. I wonder if I have keylogger on my system-what are the newest free downloads to detect these? If I find it-would I be able to sue him? I found several of his past tenants who had the same issues as I did when I lived there.