Yes, Werner's death is criminal. It could have been prevented. Six-year-old Werner, along with the rest of the family, is being punished for having Communist affiliations. He's being punished with poverty and lack of medical treatment. He is not alone.
The book thief had struck for the first time – the beginning of an illustrious career. (5.119)
Liesel's book stealing never quite qualifies as criminality, unless you're being strict. As Rudy points out, it's almost silly to call taking books from Ilsa Hermann's library "stealing." Her book thievery presents a pleasant counterpart to the very real crimes of the Nazis.
The Star of David was painted on their doors. The houses were almost like lepers. At the very least, they were infected sores on the German landscape. (8.43)
Being a Jew in these times means being a criminal. There is no move a Jew in Nazi Germany can make that isn't considered a crime.
Although something inside her told her that this was a crime – after all, her three books were the most precious items she owned – she was compelled to see the thing lit. (18.12)
She's at the Hitler's birthday celebration book burning, of course. Humans will be fascinated with crime so long as it exists. But, Liesel could have at least thought about stopping the books from being burned. Why doesn't this occur to her?
"Did the Führer take her away?" (19.15)
With Hitler's birthday comes a grim realization for Liesel. Her mother's disappearance can be traced back to the birthday boy himself. This realization is very important to all her future actions and her general development.
"Sorry it's taken so long. I think people have been watching me. And the man with the identity card took longer than I thought […]." (23.19)
Max's best friend Walter Kugler is about to go to Poland to fight on the side of the Germans. Of course, he's been drafted and wouldn't have gone of his own accord. It must make him feel like a criminal. By helping Max, he's committing a crime with a death penalty. But, we bet this doesn't make him feel like a criminal in the long run.
[…] but it was the stealing that cemented their friendship completely. […] it was driven by one inescapable force – Rudy's hunger. The boy was permanently dying for something to eat. (24.63)
This highlights Himmel Street poverty, which has only increased since the war began, due to rationing. It's also due to the fact that there were no more Jewish customers. Again, Rudy and Liesel's criminality seems the opposite of criminal, other than the ham-stealing incident.
"When a Jew shows up at your place of residence in the early hours of the morning, in the very birthplace of Nazism, you're likely to experience extreme levels of discomfort. Anxiety, disbelief, paranoia" (33.4)
This one is pretty self explanatory. In Nazi Germany, crime takes on all kinds of new meanings.
She also realized it was most likely these sodden days at the Hitler Youth that fed his, and subsequently her own, desire for crime. (39.82)
We see this pattern over and over again. The crimes committed against Rudy by Hitler Youth leaders help cause Rudy to commit some crimes of his own.
Liesel Meminger was a criminal. But not because she'd stolen a handful of books through an open window. (54.134)
Here, Death is referring to Liesel's inability to do what she thinks she should – apologize to Ilsa Hermann. In Liesel's code, failure to apologize is a great crime. So, she does apologize to Ilsa in the long run.
[…] Hans Hubermann held his hand out and presented a piece of bread […]. (58.62)
Feeding the Jewish prisoners on their way to Dachau is obviously considered a crime by the Nazi guards. It can also be seen as an act of non-violent resistance to what the Nazis are doing. It might seem like a small thing, but it was big to the Jewish people who saw it as an act of true kindness.