These are both leaf beetles (family Chrysomelidae). The first one is not a bombardier beetle (that would be in Carabidae), but one in the Galerucinae subfamily. It may be Sermylassa halensis. The other one is in the Chrysomelinae subfamily, and I think it could be the common Chrysolina fastuosa. Take a look at the photos in this gallery of German leaf beetles to check other species as well.