Each episode begins with a crime being committed. Crimes involve; robberies, shootings, beatings, stabbings, poisonings, hit and runs, murders etc. Gruesome as these may sound in theory, they are much tamer when shown particularly in comparison to other crime shows such as Criminal Minds or Law & Order.
The strongest instances of violence in the first season, which the viewer should be aware of are in the pilot episode, where a bomb blast kills, injures and maims several people. There are vivid depictions of injury detail present.
Episode 3 features a homeless man brutally beaten to death by two men. They first knock him down with a wine bottle over the head and then stomp and kick him until he is no longer moving. The impact of the scene is somewhat lessened by the rapid interspersion of camera cuts to fireworks displays which are loud and intense. Albeit normally this would heighten impact, in this scenario it does the opposite.
Episode 9 features a stonemason bludgeoned to death with a hammer/mallet. The deed is seen committed via shadows. Blood-spatter is present as well as the sound of the hammer connecting with brain matter.
A great deal of the crimes occur off-screen where they are implied, sometimes with sound. In other scenarios bodies are discovered by people.
The violence in Inspector Rex is both moderate and mild depending on the episode. In vary rare instances has the violence been strong.