Some of your "facts" are wrong.
The Denver shooting was carried out by Desmond Holly who was not transgender.
The Georgia shooting was carried out by Colt Gray. The social media claims that he was transgender were wrong. There is no evidence that he was trans.
You are correct about the Nashville shooting. That was carried out by Aiden Hale, a woman who identified as a man (by the way, those on this thread who say that women don't carry out mass shootings are wrong - they are rare but they do happen).
The most recent high profile school shooting in Colorado was the one in Denver, which I have already dealt with. Prior to that we go back to Columbine, where both shooters were male. Neither was transgender.
The Minnesota shooter had identified as transgender at one point, but no longer identified as such by the time of the shooting.
There is little evidence that the Iowa shooter, Dylan Butler, was transgender. His social media displayed some LGBTQ symbolism and an image of graffiti saying "love your trans kids", but that does not mean he was himself trans.
People on the American right such as Donald Trump Jr, Elon Musk, Marjorie Taylor-Greene, Ted Cruz and others like to push the idea that school shootings are being carried out by trans individuals, but the evidence does not support them. For example, all those I have named claimed that the Lakewood Church shooting in 2024 was carried out by a trans individual, but the perpetrator was a biological female who never identified as anything else.
As my posts elsewhere show, I am not a supporter of the trans-rights movement. It is true that the offending patterns of transwomen (i.e. men who identify as women) are identical to those of men, with the exception of violent sex offences - transwomen are more likely to be violent sex offenders than men (although, to be clear, violent sex offenders are a small minority of both men and transwomen). However, it does not help the debate to perpetuate social media myths circulated mainly by the American right suggesting, wrongly, that trans individuals are responsible for most recent mass shootings. They are not.