Here in Switzerland, hand-shaking was even more common than in the US. It was expected of everybody. School children would even shake hands with their classmates and teacher before leaving. Covid cancelled most of that, and it’s far less common today than it was.
Panel 4, it looks to me as if Marcus has just spotted something which really alarmed him. Those eyes are not directed at Dick despite the questioning. He saw his killer coming but didn’t say anything, like deer in the headlights.
I like the drawing style too. It feels like a throwback to classic things like the old Dick Tracy TV cartoon series. I wouldn’t want it as the normal style, but it makes a pleasant change for a while.
In some countries like the UK we don’t have deputising, however any civilian acting in good faith to assist a police officer is generally covered like this without having to be “commanded”. I’ve been assisted by a member of the public in making an arrest myself (he was an off-duty prison officer). The idiot crim pleaded guilty on that one, so there was no dispute about it.
As a historical note, the medieval law on the English/Scottish borders was such that the penalty for refusing to aid in the lawful pursuit of a criminal was harsher than the one for the original crime!
I just love these guys.