Maybe. Courts have held that driving at least 90 MPH in a 55 MPH zone, in addition to other factors, and causing the death of another person are sufficient to support a conviction of criminally negligent homicide. However, proof of speed alone will not support a finding of criminal negligence. It is important to talk with a lawyer who handles criminally negligent homicide cases to determine whether, under all the circumstances, your conduct rises to the level of criminal negligence.