A surge in robberies at licensed cannabis shops — including a pistol-whipping, gunshots and killings in Washington state last month — is helping fuel a renewed push for federal banking reforms that would make the cash-dependent stores a less appealing target.

“It makes absolutely no sense that legal businesses are being forced to operate entirely in cash, and it’s dangerous — and sometimes even fatal — for employees behind the register,” Washington Sen. Patty Murray, the third-ranking Democrat in the Senate, said in a statement emailed to The Associated Press.

Although 18 states have legalized the recreational use of marijuana, and 37 allow its medical use, it remains illegal under federal law. Because of that, big banks and credit card companies have long been reluctant to work with the industry, leaving the businesses heavily reliant on cash and making them attractive marks for robbers.

On the annual 4/20 marijuana holiday Wednesday, Murray held a news conference at a suburban Seattle cannabis store to say she will prioritize marijuana banking reform as part of her work as a key negotiator on a conference committee that is ironing out differences in House and Senate versions of a major federal competitiveness and innovation bill. [Read more at NPR]