[6] Brian Isaack Clyde (September 30, 1996 – June 17, 2019), a 22-year-old male,[7] was a private first class in the U.S. Army, and was honorably discharged[5] after serving as an infantryman from August 2015 to February 2017.

[5] At the time of the shooting, Clyde had recently graduated from Del Mar College in Corpus Christi, Texas, with an associate degree in applied science in nondestructive testing technology.

[8][11] Clyde appears to have self-radicalized online,[12] posting memes related to the incel subculture that appeals to men who feel lonely and alienated, and, ultimately, getting "sucked into a hateful vortex that tells them that their lives are only valuable if they go out bringing death" to others.

[17] In April 2019 he posted a meme suggesting that combining eco-friendly and libertarian ideas with far-right authoritarianism, symbolized by what the Daily Beast describes as "a green flag with a Nazi swastika in the middle", could be the "solution to all of our nation’s political problems.

[18] A Maryland Air Force base was inspired by the Dallas shooting to initiate a program teaching personnel to recognize the warning signs that "introverted, sexless individuals" may be drawn to the "incel" online subculture.