While general felony enhancements focus on the overall record, Missouri law treats offenses involving controlled substances with a specialized set of rules. Under RSMo 579.170.1(2), if you have just one previous felony conviction related to drugs to face an enhanced (greater) prison sentence.

1. Defining the “Prior Drug Offender”

According to RSMo 579.170.1(2), a “Prior drug offender” is someone who has been found guilty of any felony offense related to controlled substances.

• Any jurisdiction: This includes felony convictions under the laws of Missouri, the United States, or any other state, territory, or district.
• Controlled Substances: The prior conviction must specifically relate to substances listed in Schedules I through V, as defined in Chapter 195.
• Finding of Guilt: This status applies to those who have been “found guilty,” which includes jury verdicts, bench trials, and guilty pleas (including a suspended imposition of a sentence (SIS).

2. The +1 enhancement

The primary consequence for a prior drug offender is that the sentencing range for imprisonment in the Department of Corrections (DOC) is one class higher than the actual charge. (RSMo 579.170.4)

Current Drug Charge	Normal Range	Prior Drug Offender (+1 Enhancement)
Class E Felony	Up to 4 years	Class D Range: Up to 7 years
Class D Felony	Up to 7 years	Class C Range: 3 to 10 years
Class C Felony	3 to 10 years	Class B Range: 5 to 15 years
Class B Felony	5 to 15 years	Sentenced as Class A: 10 to 30 years or Life

3. Removal of Jury Sentencing

Just like general prior offenders and persistent felony offenders, a prior drug offender loses the right to have a jury determine their punishment (RSMo 579.170.3)

4. Pleading and Proving the Prior

For these enhancements to apply, the state must follow the requirements of RSMo 558.021. The prosecutor must “plead and prove” the prior findings of guilt to the judge before the case is submitted to the jury.