The evidence that the commonwealth needs to find an alternative funding source for Pennsylvania State Police is piling up.

The latest addition: revelations that despite receiving hundreds of millions of dollars from the state’s Motor License Fund, the agency can’t say exactly what it did with the money.

That admission, from an agency spokesman on Monday, has raised eyebrows in the state Auditor General’s office, which rightly suggested that it might be a good idea to fix that and other “errors” surrounding the agency’s funding going forward.

The other problem is that state police received $755 million from the fund during the 2015-16 fiscal year — $222 million more than the agency should have, according to a legislative report.

Not being able to account for how hundreds of millions of dollars in taxpayer money was spent, beyond “appropriate and justifiable” purposes, is bad enough. It’s beyond belief that the state would siphon off money earmarked for a much-needed purpose — namely, maintenance of Pennsylvania’s ailing roads and bridges — to give it to another agency, and then fail to require that agency to track exactly what those funds are being used for.

But not being able to account for such a large sum of money at a time when you’ve received hundreds of millions more than you were supposed to? That’s a whole other level of dysfunction.

The good news is that the antidote is apparent. Not only that, the fix can be effected as part of a solution to a larger problem. Because the bottom line is that Pennsylvania shouldn’t be using money from its Motor License Fund to buttress PSP’s annual budget.

Enter the solution: a proposed per-resident fee that would be paid by municipalities that don’t have local police protection. There are nearly 1,300 of those municipalities across the state, and serving them costs PSP about half of its $1 billion annual budget, according to the agency.

Imposing such a fee isn’t likely to be popular with residents of those communities, but if legislators needed another excuse, now they have one. The state needs to do everything it can to make sure taxpayers know what their money is being used for, and why fees are being levied in the first place.

That’s the only “appropriate and justifiable” way to manage the billions of dollars in public money Pennsylvania collects each year.