Was Peter's father Swing Kids killed?

The same goes for Peter.

Peter is forced into joining the HJ by being arrested for trying to steal radios as a retribution against an abusive block captain as well as as a gift to Arvid following a bad fight. Thomas agrees to join the HJ in solidarity. He promises that they can pretend like Nazis during the day and live it up as swing children at night.

The same goes for Arvid in Swing Kids. Plot. Plot. They have a great time dancing and enjoying the music. Arvid, who has a clubfoot, can barely keep up with the rest of the boys as they leave the club.

This is how Peter and Thomas get the radio stolen.

Peter and Thomas take a radio from a bakery to apologize to Arvid. Thomas accuses Hitler's father of insulting him in an attempt to cause trouble. However, Thomas is not surprised when the Nazis invade his home and take his father.

How does Arvid commit suicide?

Driven by Suicide Arvid kills himself with a broken record in the bathtub. This is a reference to the time he was beaten up rather than participating in the Nazi murders.