I found an article which explained it well, it is underreported. A lot of illegals are only counted as illegals in the justice system many years after they were already in prison. When adjusting for those later counted as illegals, the rate of crimes illegals commits is well above the Texas average.

https://cis.org/Report/Misuse-Texas-Data-Understates-Illegal-Immigrant-Criminality

I found an article which explained it well, it is underreported. A lot of illegals are only counted as illegals in the justice system many years after they were already in prison. When adjusting for those later counted as illegals, the rate of crimes illegals commits dis well above the Texas average.

https://cis.org/Report/Misuse-Texas-Data-Understates-Illegal-Immigrant-Criminality