Q: can't empty trash, tried secure (option-cmd-shift-del) & Terminal

First, thanks.

Next, I did as you suggested and the emptying took off like the proverbial bat out of ****.... and kept going past 0.  It's now "emptying" NEGATIVE items (i.e., the items to delete count is getting more negative)!

That would mean that it's actually putting things back into the trash (in a strictly numerical sense)...

It's slowing down now, but I'm afraid to stop it. It's at -68,414, and still going.  Yikes!

Third, what's the point of "securely" emptying the trash if you can do it unsecurely just as easily?

And it's still going...

Up to -384,769

It finally stopped counting, but there's still trash in there... Backup folder contents.

I told it to empty and it said there were locked items.

I told it to empty everything, and heard the crumpling, but those items are still there...

Now what?

I opened the Backup folder, and there are 4 copies of pretty much the same thing:

Backups.backupdb > My computer name > a numbered file > My HD name > system > Library > CoreServices > and finally (a locked) boot.efi

Now, how I got multiple copies of it, I don't know - prob, as you say, from Time Machine or something.

I tried unchecking the LOCKED box under Get Info, but can't because it's grayed out.

I tried taking it out of the trash so I could uncheck the LOCKED box, but it just copied the files. So now I have twice as many when I put those back in the trash!

I tried a bunch of stuff with Terminal and immutable files, but everything is the same...

Erasing my backup volume sounds like something I don't want to do...

Well, thanks for trying!

Anyone else?