This post by Brian Vastag at the WaPo's health blog, The Checkup, does not relate directly to crime.  What it does discuss, among other things, is "publication bias."  Studies on one side of an issue may be more likely to be published than studies on another side, so just counting published studies may not be valid to get a feel for the state of the research.  There is a financial incentive to publish studies showing that new, patented, expensive drugs are effective and more so than the old off-patent drugs.  Nobody has much incentive to publish studies going the other way.  "Instead, the negative studies were buried on the FDA website, where only a specialist with a background in statistics could understand what they meant."

Is there a "publication bias" in criminal law?  The kind of financial interest this post notes for drugs is not present.  I suspect that Political Correctness has an effect, though, on what gets published in academic journals.