That's because nobody lives there! You could fit the entire population of Wyoming into Düsseldorf once or Cologne twice.Moved here as it is more appropriate:
Having searched for a bit, the only reference I can find was three people shot at a party in Essex on 13 June. None died.
I wonder how many similar shootings of 3+ people happened in the US in the past month? Their population is 5 x larger, so I would expect it to match.
97, according to Wikipedia. List of mass shootings in the United States in 2020 - Wikipedia
I will give @Steamboat his due, however - none this year in Wyoming.