Apparently, their paper, "Perceived Criminality, Criminal Background Checks, and the Racial Hiring Practices of Employers," was first published in 2001 and has been republished over several drafts. The June 2005 version is the most recent version I could find freely available on the internet (published on the Berkeley website of Stephen Raphael, one of the paper's authors). The paper's abstract:

In this paper, we analyze the effect of employer-initiated criminal background checks on the likelihood that employers hire African-Americans. We find that employers who check criminal backgrounds are more like to hire African-American workers, especially among men. This effect is stronger among those employers who report an aversion to hiring those with criminal records than among those who do not. We also find similar effects of employer aversion to ex-offenders and their tendency to check backgrounds on their willingness to hire other stigmatized workers, such as those with gaps in their employment history. These results suggest that, in the absence of criminal background checks, some employers discriminate statistically against black men and/or those with weak employment records. Such discrimination appears to contribute substantially to observed employment and earnings gaps between white and black young men.

The version published in this month's edition of the University of Chicago's  The Journal of Law and Economics [vol. XLIX (October 2006)] can be purchased for $6 at the university's website.

The study suggests that race still plays an inappropriate role in many hiring decisions. In my HR experience, I found that this influence is often not perceived by even the best-intentioned hiring managers.  Background checks are one indicator that an employer has a well designed selection process, as are defined position competencies, behavior interviewing techniques, and other other methods of ensuring that the employer selects the best candidate for each position, regardless of race or other irrelevant factors.

The take-away for the screening industry is another tool to reinforce human resources' certainty that background checks can help them build an effective, safe, and now, diverse workforce.