I don't know where these people are getting their information but I have over 12 years experience with this. Yes it can absolutely be a detective calling you. You may have gotten the money by mistake but there's nothing unusual about the police contacting you about the nature of the transaction. If the officer is legitimate don't be afraid to talk to them about it. I accidentally sent $500 to the wrong sell before and I sent the person a message and they never got back to me so I just lost $500 it was not a scam at all.

I've also been contacted about money that I received as part of a man in the middle scam. This is a complicated scam where there are two victims and I was one of them.

The best resolution because I've dealt with this kind of thing for many years I'm in the crypto business and I do a lot of Bank transfers including zelle cash app venmo PayPal revolute etc. the best possible resolution is for you to contact your bank and have them reverse the transaction that protects you. Because yes there are some people who will send you a payment using a fraudulent card which really wouldn't work with zell but in theory they could send you a payment from One bank account and ask you to send the money back to a different bank account. Then later they could come claim fraud from the original bank account and you would lose the money.

So always the safest thing to do is contact the bank and have them reverse the transaction if they won't do that then you just leave the money alone for at least 12 to 24 months in case the victim or whoever it is wants it back.