They will accuse you of a crime you didn't commit and possibly demand payment in bitcoins, gift cards, etc. Scammers have gotten smart these days and will do research on your local police and use their names. They will even spoof their phone number to appear more genuine. They will use high pressure tactics to steal your money. A police will never call or text you informing you about your warrant, they do not do this because people might flee when they hear that they have one
Btw I nearly killed myself over this when I saw their text and voice message, it sounded so convincing.
I am so sorry that this happened to you. Wondering if my approach will help..,
1. I don't open the door to anyone. If police show up, I can speak to them through a camera at best, or via a closed window. Even if they manage to convince me that they really are the police, I will not open the door - I will call the emergency line fornthe police to clarify if there is some truth and if these officers actually exist and would expect the control room to clear with the people standing outside that they are genuine.
2. I am ex-directory, ex everything and am not on social media. I do not answer calls to unknown numbers anf if someone left a message saying that there were the police - I will follow point number one and would expect everything in writting and will copy all communications to another part of the force.
Even if what they had said was true, demanding payment will make them corrupt and they should be reported for corruption.
I am so sorry that you went through this - those damned scammers will try the same techniques with 1000s of people and some poor innocent person will fall for it and they make the money that way - feeding off others people misery. Just best not to trust anyone till they through your own ID verification process..,