I have a permit, my wife does not. I sometimes have to lock my carry piece in a box in my car that is under the seat and cabled to it. For example, when I take the kid in at daycare, prohibited place and all. My question is, if I inadvertently leave the pistol locked in that box, loaded as I do when I carry, if my wife takes my car (we frequently switch vehicles) is she going to get jammed up for possession or is not possession if she doesn't have the key?

Make sure she knows the words, “I do not consent to any searches.”

Unloaded and cased in the passenger compartment requires no permit. If it’s loaded, a permit is required.

Same here. Her dad lost a brother in a negligent storage incident when they were children and needless to say she didn't grow up handling firearms and being taught safety like I was.

I thought this was the case from reading the statute but I wanted to make sure I wasn't missing something in caselaw or whatever. I'll have to come up with a different plan. I assume a mag loaded on an empty chamber is the same as ready to fire right?

In all honesty, I doubt it would ever be an issue. My wife has been pulled over by the cops one time in 40 years but I can't take any chances.

MN Law
Transporting Firearms Transporting a Firearm in a Motor Vehicle The general law pertaining to transporting a firearm in a motor vehicle stipulates that no person may transport a firearm in a motor vehicle unless the firearm:

is unloaded and in a closed gun case expressly made for that purpose; ?
is unloaded and in the closed trunk of the motor vehicle;
or ? is a pistol carried in compliance with the carry permit requirements of the Gun Control Act.103

Yes, loaded mag in the gun is a loaded gun.

This is one of the reasons my wife has her carry permit

+1000

This is about as clear cut as it gets.

I bet some %^&U* DA could make the argument if the cop would arrest you for it.

Just to be 100% clear, a cased firearm is what we are discussing... People vs. Hale is not part of this discussion.

If the loaded magazine is in the magwell, its "loaded".
Round in the chamber OR round in a cylinder OR round in a magazine in the magwell... its a loaded gun.

BTW: Chamber flags have nothing to do with a gun being loaded/unloaded in the eyes of the law.

Now, as I have been told by the DNR, if its on a carrier and OUTSIDE the action, its not loaded.

But I agree, it may be deputy law dawg that wants to make an example of you.

That said, not all LEOs are consistent. You can legally cross a highway/road with rounds in a buttstock or sling carrier with a cased firearm. There is (currently) no requirement in MN to store ammo SEPARATE from the firearm.
EXAMPLE: Shotgun shells on a side saddle does not make it a loaded firearm. If they do a breach check and a round will be chambered when it gets closed, its LOADED!!!

If she doesn't have the key to the lock box I'd argue she isn't "in possession or control" of the pistol and therefore isn't carrying or transporting it.
But that's an argument lawyers get to make after she's been arrested for it.

Is possession or control required for the definition of transporting it while she’s transporting it?

Just assume she is operating under constructive possession.

If it's in a locked box that she can't open that's bolted to the vehicle how would anyone know, 1st of all,  whether there's a firearm in it and 2nd whether it was loaded? Additionally, since I assume none of you are foolishly allowing random searches of your vehicles for petty traffic stops, no officer should even have an inkling that there's a box that could have a firearm in it in the vehicle anyway.

Hmmm let me see. K9 unit decides he wants to search. I mean after all the dog said there is a gun in the car right next to all that weed.

I think you're really reaching for that one.

I had my wife get her permit for same reasons as OP has concerns about. I took the class with her as my renewal, and the instructor brought up a decent point that I've been pondering to date -

"on or about the person's clothes or the person" - My interpretation: I'm good if it's on me, or near me. I believe 'or about the person' indicates within a reasonable reach though can't find the legal context. So if you, as a permit holder, have a loaded (by definition of the law) pistol stowed somewhere in the back of your vehicle and not actually 'about the person', you're in violation.

Now taking that thought process a little further: I placed my loaded pistol in the lock box under the seat of my car in the parking lot at my place of work. Exit the vehicle, go into the office. It is no longer on or about my person, or necessarily in my control at that point. Have I broken the law?

One of the buildings I frequent has had workplace safety meetings conducted with the assistance of MN State Troopers, and while employees are prohibited from carrying on premise, it has actually been recommended by the state trooper doing the training for permit holders to do exactly as described above - lock the loaded pistol in the vehicle. It was specifically recommended not fumble around with unloading to reduce the possibility of other employees being concerned with a person playing with a gun in their vehicle.

Didn't mean to de-rail, but thought it relevant to the discussion. I was honestly never too concerned when my non-permit wife would take my vehicle with a locked up pistol under the seat - as rare as it was. Coincidentally enough now that she has her permit, I never leave it locked in the vehicle as I've come to terms that it's at more risk to be stolen than we ever were of being victim to some kind of legal technicality.

No. Your interpretation is wrong. If you have a valid permit and a gun in your car you're not violating the statute you quoted.
The question in this thread is if a non-permit holding spouse would violate the statute in that car with a gun locked in a box, which in my mind turns on if a person is in "possession or control" of an object that the person cannot access, touch, or use unless they have a key to the box or destroy the lock.
Leaving loaded guns in cars when the permit holder isn't there is a bad idea (theft risk), except of course in the case where you need to go into a building where you can't carry as you suggest, but it also isn't a violation of the statute.

I go back and forth on it - I suppose it comes down to what factors define being in control of it.

Blue text is guidance from the House Research Department on the exception for transporting handguns in vehicles for those with Permits To Carry.  (Handguns carried under permit can be transported anywhere in the vehicle, in any condition, whether the permit holder is present or not.)

Red text is guidance from same about constructive possession.

https://www.house.leg.state.mn.us/hrd/pubs/ss/ssfiretrns.pdf