Any person who is facing a potential criminal charge should absolutely NOT give a statement to the police concerning the underlying events. The police are not trying to help your son. There is no benefit to your son speaking with the officer. In fact, the police want to take a statement from your son because your son's statement will help them build their case.
Your son needs to consult an attorney who defends clients facing serious criminal charges. We represent clients on such matters all the time. Feel free to contact our office for further information.
One final thing. Please do not post any further information about your son's case online. The police and prosecutors can read what you post on a public forum such as this.