I once had a boss who was an IPD officer and he carried a Benchmade Autofolder. Whether or not they are legal for LEOs, apparently they are easily overlooked.
Most places I've seen selling autos will sell to any Military/LEO/EMT/FF with an order placed on department letterhead, they don't bother to check local laws, that's up to the purchaser.
Another interesting caveat... I know in the past it was legal to sell an automatic knife KIT in Indiana, just posession of the finished product was illegal (yes, I found out the hard way with a decent cop who let me smash it and trash it and be on my way about 13 years ago...) Are the knife kits still able to be legally sold? Not something I've kept up on lately.
It was a junk Italian stiletto copy anyway, heh... Bought it when I was probably 15 or 16 from the knife shop that used to be in Union Station in Indy...