How do you secure the trailer?
The same as I do my open trailer, with a lock through the hitch. However with the trailer sitting between the garages, it's slightly hidden to traffic going by.
If somebody wanted it, they are going to have to back down through the yard, which isn't going to happen if it has rained. Anybody with half a brain will know that they might get stuck and probably best off to a have a 4wd truck. Then to back it out, the daughter's car or her BF's car is probably sitting behind it. So they would need to have that car not sitting there.
I work 24 on/48 off, so they need to figure out my schedule when the armed owner is not at home. The dog we have now, is a barker if he hears something.
Then to top it off, the wife is the admin assistant to the Sheriff, and I know all the deputies. They tend to sit in our driveway to run traffic or if they are doing paperwork. Many times if I'm outside, one of them will stop to shoot the bull for a few minutes. You can also include the Post Commander for the state patrol is a friend and lives a few miles down the road, He'll occasionally stop for a few minutes and see what's up. Trust me when I say that people know where LEOs sit as I have had many people ask me about it.
I also have good neighbors as we all what out for each other and basically know who should be around and who shouldn't. We have all questioned people that are at others homes. The neighbor to the west of me is also a Correctional Officer for the Sheriff's office and works various shifts coming/going at various hours. Also, being on the local volunteer dept, those guys watch what happens as they go by day to day or when going on calls. Believe it or not, you can add in the local EMS provider goes by on a regular basis with eyes open. More than one time, I have had one of them say something to me about what I'm working on at home when I'm at work and on an EMS call or when they come to one of their fire calls.
That being said (and long winded) I am very fortunate to have many friends and lucky to have people of various employers looking out for my place, but if somebody wants something bad enough, they will get it.