Re: "shot dead at his house while playing dominoes"
Many retail outlets now have small portable card readers that have a wireless link to the shop's server, especially if the staff have to walk around to customers. ( My dentist's reception desk also has one of these, maybe because it's more convenient that a cabled reader or a fixed one.)
In a restaurant, the staff would present you with the bill and the reader, put your card in the reader for you and ask you to enter the amount on the reader keyboard, press Enter, then your PIN and press Enter; hinting that a tip added to the amount would be most welcome. The card never leaves your sight.
If they have a payment desk, it's the same process but the card reader is fixed to an adjustable stand of some kind. Many people, especially in large groups dining out, prefer to leave cash on the table as a tip, knowing that that staff are more likely to get it if it lands in their hands directly.