Never pay down a deposit in a bank account until you have met the seller, seen signed a purchase agreement.
No serious private advertisers ask for a down payment before you meet.
Receiving an email with an in-scanned ID does not mean that you have identified the sender. You do this on the spot, when you sign a purchase agreement.
Charming Squirrel is looking for a home. Squirrel ended up in the shelter where I volunteer, recently: she was given away by a person who could no longer keep her at home. Squirrel loves people, but doesn't like other cats and is very sad in the shelter. She is about a year old, she is very affectionate and contact cat.