State crime labs are simply a rubber stamp on whatever story the prosecutor has decided on presenting ahead of time. It's not well known, but crime labs are paid per conviction [1]. Intentional contamination of evidence, falsification of results, and the use of unreliable methods are entirely routine and expected within these departments. They are corrupt through and through. No state crime lab report should ever be considered at all credible in any way.
Occasionally large-scale corruption comes to light such as when a Boston crime lab falsified drug tests on a massive scale [2] or New York state police were found to have fabricated fingerprint evidence for nearly a decade [3]. The "forensics" field has been embroiled in a steady stream of scandals [4]. Far from being isolated incidents, this is the norm within law enforcement.
The relevant passage in the source for this claim[1]:
Funding crime labs through court-assessed fees creates another channel for bias to enter crime lab analyses. In jurisdictions with this practice the crime lab receives a sum of money for each conviction of a given type. Ray Wickenheiser says, “Collection of court costs is the only stable source of funding for the Acadiana Crime Lab. $10 is received for each guilty plea or verdict from each speeding ticket, and $50 from each DWI (Driving While Impaired) and drug offense.”117 In Broward County, Florida, “Monies deposited in the Trust Fund are principally court costs assessed upon conviction of driving or boating under the influence ($50) or selling, manufacturing, delivery, or possession of a controlled substance ($100).”118
Several state statutory schemes require defendants to pay crime laboratory fees upon conviction. North Carolina General Statutes require, “[f]or the services of” the state or local crime lab, that judges in criminal cases assess a $600 fee to be charged “upon conviction” and remitted to the law enforcement agency containing the lab whenever that lab “performed DNA analysis of the crime, tests of bodily fluids of the defendant for the presence of alcohol or controlled substances, or analysis of any controlled substance possessed by the defendant or the defendant's agent.”119 Illinois crime labs receive fees upon convictions for sex offenses, controlled substance offenses, and those involving driving under the influence.120 Mississippi statues require crime laboratory fees for various conviction types, including arson, aiding suicide, and driving while intoxicated.121 Similar provisions exist in Alabama, New Mexico, Kentucky, New Jersey, Virginia, and, until recently, Michigan.122
Other states have broadened the scope even further. Washington statutes require a $100 crime lab fee for any conviction that involves lab analysis.123 Kansas statutes require offenders “to pay a separate court cost of $400 for every individual offense if forensic science or laboratory services or forensic computer examination services are provided in connection with the investigation.”124 In addition to those already listed, the following states also require crime lab fees in connection with various conviction types: Arizona, California, Missouri, Tennessee, and Wisconsin.125
Glen Whitman and Roger Koppl point out that “the very choice to submit a suspect's sample to the lab makes the lab more inclined (than it would be otherwise) to announce a match, indicating that the suspect is guilty.”126 The forensic scientist must evaluate ambiguous evidence, but give, generally, a binary judgment that the evidence does or does not match. Whitman and Koppl explain why the probabilities given in DNA testimony are not usually an exception to this binary nature of forensic-science testimony.127 In this situation, even the most rational scientist must choose what to say. The choice will usually be influenced by scientific analysis done in the crime lab. But if the evidence is ambiguous, as it often is, then two other factors matter even for perfectly rational forensic scientists. The scientist is more likely to inculpate the defendant (1) the higher the forensic scientist's “prior” probability of guilt, which is the probability before the forensic evidence is examined, and (2) the weaker the scientist's desire is to avoid convicting the innocent relative to her desire to convict the guilty.
So, the claim does appear to be true, at least in some states.
Seriously: what?