All I know is what I read in the papers ...

The two key paragraphs in the mountain of Journal Sentinel coverage of the Brookfield spa slayings:

"Last week, Zina Haughton received a restraining order against her husband. On Saturday, Radcliffe Haughton purchased the .40-caliber handgun he would use to shoot seven women, killing three Azana workers, including his wife.

"The injunction prohibited Haughton from buying a gun from a dealer. But Haughton sidestepped federal law by purchasing the gun privately, which meant a background check is not required. Private sellers also do not have to follow a 48-hour waiting period, required for gun dealers in Wisconsin. The waiting period was intended, in part, as a cooling-off period in domestic violence cases."

Wisconsin Anti-Violence Effort has tried for years to get state law changed to require background checks on all gun sales.  Last session, not a single legislator would even introduce the bill.