This study is reported on several news websites.
Here is the paper.
To sum, providers are disproportionately large number of female victims of homicide.
When providers can screen clients through Craigslist or TER, the can effectively choose safer clients.
The overall effect it to drop female homicides by 17.4 percent.

In fact I would expect it.  But I do wonder about this paper when it has "DRAFT - PLEASE DO NOT CITE OR SHARE" in big letters on the top page.

suggest that this is not an alt fact.
The study is also reported on in Huffpost on October 12 by Allison Bass