I received a garnishment on someone who is paid as a 1099 contractor. I am a Broker of an RE company these monies would be coming from commissions and we are located in the State of Missouri

Welcome to AMHD. Take a look: Section 525-010 Who may be summoned as garnishees. (http://www.moga.mo.gov/statutes/C500-599/5250000010.HTM)
And generally: RSMO-Chapter 525 (http://www.moga.mo.gov/STATUTES/C525.HTM)