since the guy he was looking for (previous tenant) is in jail for possession I'd say your three options have only about a 1% chance of being the reason he was there. Jail for possession means an amount more than the slap on the wrist personal use
And the problem was the drugs?
Let's see.
He's a loan shark, he wants his money back.
He loaned a friend a car, he wants his money back.
He thinks his wife is hiding in your apartment, he wants to "see" her.
Seems like the problem was a dirtbag was trying to collect. The object doesn't matter.
Glad you AND your pup are fine, and you weren't forced into a shooting scenario. The BG is lucky he wasn't shot when he forced that door open.
As noted, it might be a good idea to talk to the landlord and switch apartments. Scumbags like that don't usually take 'no' for an answer, unfortunately.
But, wait! I thought drugs were a 'victimless' crime?
My point was about the "victimless crime".
If drugs were legal/illegal has no bearing.
A guy came to his door looking for a person, and was willing to attempt to force entry.