Yes, Trump was indirectly responsible for the increase last year.
We had non-stop BLM/Antifa riots with massive efforts to defund the police. The efforts were part of the election-year war on America that was a key part of the Democrats’ strategy to remove Trump from office.
Biden has not reversed the effects of the war on America, and the number of mass shootings have continued to increase.
Without Sinema and Manchin, Dems would already have ended the legislative filibuster that they used profusely throughout Trumps term, taken away control of voting from the states to hand it to the Democrats, and given themselves two permanent new Senate seats by granting statehood to a city. So say Sinema and Manchin aren’t authoritarians, not Democrats.