Ulrich Boser on the Holocaust Museum shooting and museum security: "Museums are, after all, museums. They suffer from a Catch 22. On one side, they have to show their treasures. On the other side, they have to protect them. ... Keep in mind that a museum can't pat down people before they come inside. Ultimately, if people want to kill and they have access to weapons, it's hard to defend oneself. Not impossible. But very hard."