There is grey line when it comes to Autism and criminality, because Autism is treated as a spectrum disorder.
I wouldn't be surprised if a higher-functioning person with any developmental disorder committed crimes, because by definition of being high-functioning means that you are capable of doing neurotypical tasks regardless if you have a developmental disorder and it is not uncommon for high-functioning people with developmental disorders to develop personality disorders that may influence but does not cause criminality.
But if a person with Intellectual Disability was suspected of commiting murder, not impossible but it is very rare, It would still be very strange to believe that people with Intellectual Disability have the right motivation to commit all the acts of murder, they are also less likely to develop conduct disorders and they are ten times more likely to be victims, because they have problems with Intellectual and adaptive-functioning.