Illegal Eviction or not?

First off I live in New York.

Hello, I currently live in a household of 5. Of the household there are my two parents, myself (17 years of age), my sister (22 yrs old) and her boyfriend (24 years old). My question is probably very common but It needs an answer.

For the past 15 months, my sister and her boyfriend have been living in my house. It is no secret that my parents and myself want the boyfriend to go. Yet my parents nor myself are sure as to how we should remove him. There is no formal agreement (written or spoken) as to the conditions of my sister's boyfriend's living status with us. In other words, he is a freeloader.

How do we first start by removing them, legally? Outter family members tell us that we should just lock the doors one day and not let them back. My parents have given them many deadlines to be out, and they never meet their dates, they don't leave. We have notified them for the past 6 months that we want them out, but they avoid the issue and they wont do the right thing.

Does anybody have any idea as to the status of the boyfriend's residency? He hasn't filed for this house to be his mailing address, but he does receive too many calls from creditors hunting him down. Could my parents legally just tell him to get the hell out, give him 2 weeks and then lock the doors? Others say that he is legally allowed to stay in the house as long as a resident of the house says he can, so if my parents were to kick out both my sister and her boyfriend (then possibly let my sister in at a later date when the two split up), could that be legal? Is there any way to avoid court orders and such? One other issue is that, sad as it is, my father is a city cop and he is only months away from retiring, he claims he doesnt want to make a big scene because he doesn't want to get into any trouble with his job.

Please, I need help. I myself have thought about attacking him, if he hits me back, I get a restraining order against him, there is no way he could force a minor out of his own house, legally, if any orders of restraint were placed, wouldn't they favor me and force him to leave the premisis? Im very confused on the matter and I am not sure if I should call the local police and ask them their opinions, call a lawyer, or just start a war within the household and force them out.

Any ideas? Please?? Something needs to happen, this has been going on for way too long and it doesnt seem to be getting any better. The guy lives off my friggin sister's paycheck for christ sake. He has completely destroyed her credit line and her entire life has been in termoil eversince she met him. Personally, I see my sister as a traitor, and I would be glad to see her go with him. Since she is 22, my parents should be able to just tell her to leave without any problem, and once she is gone, I guess the boyfriend could be evicted without a problem seeing how no residents of the household would invite him back... He doesnt pay rent, but I don't know how squatters rights works... Thanks!

[Souix]

You need to post this on the landlord tenant forum. Keep it brief, you are disobeying the rules.

[HomeGuru]

That's the way to keep them in line.