Do I have to blow in Missouri?

No, but if you refuse a breathalyzer test, be prepared to face the consequences.

A breathalyzer refusal in Missouri can lead to a license suspension for 1 year.  The prosecution will certainly also use this fact against you at trial.

To make matters worse, the officer can still get a warrant to have your blood drawn.  Some counties in Missouri have even created laws that allow police officers to take your blood without a warrant and without having your permission.

The Missouri Supreme Court will be deciding the constitutionality of this issue this fall.  Until then, the risk still exists.

Thus, just because you refuse a breathalyzer doesn’t mean you are off the hook.