Actually its a misdemeanour.
http://www.criminaldefenselawyer.com/re ... ssouri.htm
Assault in the Third Degree Against Certain Victims
A person is guilty of the crime of assault against a law enforcement officer, corrections officer, emergency personnel (such as a firefighter, emergency room personnel or emergency medical technician), highway worker, or probation and parole officer if he:
recklessly causes physical injury to the victim
purposely threatens the victim with immediate physical injury, or
knowingly causes or attempts to cause physical contact with the victim without the victim’s consent.
This assault crime also is a Class A misdemeanor and possible punishment is the same as a regular Class A misdemeanor, as described above.




