“In jurisdictions with this practice the crime lab receives a sum of money for each conviction of a given type. Several state statutory schemes require defendants to pay crime laboratory fees upon conviction. Illinois crime labs receive fees upon convictions for sex offenses, controlled substance offenses, and those involving driving under the influence. Mississippi crime labs require crime laboratory fees for various conviction types, including arson, aiding suicide, and driving while intoxicated. Similar provisions exist in Alabama, New Mexico, Kentucky, New Jersey, Virginia, and, until recently, Michigan. Other states have broadened the scope even further.”
http://www.policestateusa.com/2014/state-crime-labs-incentivized-get-false-convictions/