Yeah, something is weird about the whole situation. "Dad" should have given instruction, removed ammo, or locked that thing up somewhere else. And yep, gun locks are only to keep younger kids from shooting their friends/siblings. Any older person with a screwdriver, cuttters or whatever could easily get off most trigger or cable locks. A badass gun safe is better, but any step toward safety is better than none...
Typical example of someone's problem now becoming your problem. Gees that annoys me in my personal life. Gee whiz Dad, I love ya but it's your gun, you figure it out. Go put it in your own safety deposit box and give me the key.
It's a gun, not a functional nuclear device. No need to go overboard. If it's an auto pistol, the best thing is to break it down, if you're that worried. Just don't lose any parts.
OP, the Beretta 9mm has a hammer drop safety. All you need to do is keep the hammer drop safety selector in the down position (where you don't see the red dot. Red=fire.) The trigger is disengaged with the Beretta when the hammer drop safety is down. i.e., when the hammer drop is down, you can squeeze the trigger, but the hammer won't move. IF you have kids in the house, get a gun lock like the one posted earlier on the 1911. Some police departments will give you these if you call. It was part of a grant, and many have the locks if you ask. No need to panic.
Well, hope everything is resolved, and the collective wisdom of ET produced good Karma. Wish I could just have that stuff, I'd just keep it under my pillow. And hug it, and pat it, and call it George Friend of mine is going for his pistol license here, (Australia, in case anyone missed it) has to turn up to-I think it was four/five range shoots per year (compulsory) just to get started, can't actually buy a pistol for the first year, gotta use club guns etc. Then, the storage of course, Roughly $500 minimum for "home" storage, otherwise it's stored at the cop shop or other approved armoury etc. Only taken out for club shoots etc. But, hat's off to him, he's jumping through the hoops like a good little boy, he's taken his teenage boys and they absolutely love it. Sucks, actually, but it's clear the legislation is meant to weed out home security types, drug lords, half assed gang bangers, "only serious pistol shooters need apply". Oddly, the crim's still have all the guns they want.......... But, how would you know if you liked the sport, with all that red tape? Ugh, probably OT, just felt the need for a rant.
Sure, the bank will hold it. No problem. They're very accustomed to this sort of thing. Just take it to the bank, walk up to the tellers window, and pull out the gun. Then say, "i think you know why i'm here." (they are quite familiar with the procedure) They'll probably jump right to it. If you have a good bank, they'll give you excellent service. Hope i've helped.