Perhaps consider paying $25 to have a tenant report. I have any new tenant sign photos of the apartment I print out, seems that would have short circuited this. Also consider retaining an attorney to draft a lease that you can reuse.
I am very sympathetic to your troubles and your loss, but I also believe you bear some of the responsibility in not protecting yourself. I enter into all of my leases with the assumption that I will have to provide supporting evidence to a court to prosecute an eviction and likewise to defend a claim by my tenant. The moment you noticed someone else at the rental you should have drafted a notice to cease and informed the tenant you would schedule an inspection to ensure he was the only resident. Bad tenants hate getting papered! A notice to cease is awesome because it allows you to begin telling the story- your version. So when you filed for eviction and you have six different notices documenting what has transpired in real time you have effectively gotten to the judge first. Also the judge is going to see that you are a contentious and professional landlord. This has served me well- but this is only one component of my responsibilities.
I love owning a rental property because it allows me to engage in different jobs and responsibilities. I find that to be very exciting. But I also want to be the best in my duties... so look at it a different way:
If you hired a broker to vet your tenants and a property manager and you found yourself in eviction court every 2 years would that be acceptable to you? On a three family house? I would find it unacceptable on a 10 unit building. I would fire both immediately. Also, if I was one of your other tenants I would be very put off by all of the drama and nonsense going on because my landlord rented to jerks.
I hold myself to a very high standard and I also have a tremendous sense of responsibility to my tenants, neighbors and town. But I also find it very fun and I have had a great mentor without whom I would be lost.
I highly recommend the book "Landlording." But also consider using a broker and property management company, with the trouble and financial loss you are dealing with now it would more than pay for itself.
The Asbury Park Press just did an excellent 4 or 5 part series on the state of landlord/tenant around the state. I was appalled at what landlords get away with and what tenants are put through. From decrepit, overcrowded apartments to using the LLC to duck legal responsibilities, it is bad. We all know they are the vast minority, but they are the ones that are going to dictate public policy and the ones people remember. And do you think there was one story on problem tenants- nope not one... and God knows there are some good stories out there.
Anyway- best of luck, I hope you can come out of this for the better!