No, he murdered his biological sister who was having herself Mengelized into an ersatz male. Takes some careful reading of the article and remembering it appears in a leading LGBT publication, “The Advocate.”
It was a biological brother (Jordan Cofer) identifying as “Megan”. Read an article that says his family was unaware of this.. weirder by the minute.
https://www.advocate.com/news/2019/8/07/report-sibling-killed-dayton-shooting-was-trans-man-jordan-cofer