How Long Can I Stay in This Abandoned Convent Before Getting Caught?

This is a low-effort run and gun scout of an abandoned convent that I got into earlier this year while on a solo road trip.
I'd attempted this one a couple of times over the years but never managed to get inside. Friends had told me that it was alarmed and there was a response, so once the alarm goes off, it's time to shoot fast while heading for the exit.
On this successful trip, I stepped carefully, looking aro-und every corner for cameras, blinking motion sensors, anything that would alert anyone that I was there.
I spotted many cameras and sensors and was able to sneak around them without setting off the alarm. Most of them were installed in a hallway corner, pointed in one direction, so I was able to shimmy along the wall the opposite way.
However, it didn't take long for one of the sensors to spot me and the alarm started blasting, so it was rapid fire shots as I made my way towards the only way out.
I got off the property and hung back about 20 minutes, waiting to see if anyone responded, but no one came.
So, I decided to head off and check another location nearby and I came back about 1 hour later, my access was still open, but my gut told me "not yet".
I sat in my car for about 30 more minutes until I decided enough time had passed, lets go back in!
Just as I was pulling my camera bag out of my car, a black SUV pulled up right in front of the building. An older man got out with a cordless drill and a bag full of screws and he headed to check on all of the doors.
So, sadly this was all that I got from this one!
