Are these normal activities for the Church of Latter-day Saints?

Three years ago, I was coming home from some late-night grocery shopping. It must have been nine, nine-thirty PM. When I turned into my neighborhood, a car with no lights on turned on to the road behind me and followed me home. They stopped at the end of my driveway and looked in my mailbox. When I got out of my car, they shouted out the window, “Are you my mother-in-law’s name?” I said “Who’s asking?” They got out of the car and said “We’re from the church”. I closed my door, and called my husband.
They asked him if he was his father’s name. He asked how they knew his father, and there was a pretty lengthy discussion. They demanded to speak to my mother in law, tried to push past my husband to come to the door. The discussion ended with my husband threatening to let the dogs (who were not liking the fear and anger energy and were going apeshit) out if they didn’t leave our property immediately.

We later learned that his parents were once members of the Mormon church – back in 1972, in Illinois. We live in Florida. His parents have been divorced for almost 30 years.

Last night, at 8:30, there was a knock at the door.I was home alone – thought it was my husband coming home.
“Hello! Are you my mother in law’s name?”

“Are you from the Mormon church?”

“Yes.”

“We’ve told you never to set foot on our property again.” * close door*

They sat out in my driveway for 15 minutes before driving off.

Is there any way I can get these people to leave us alone for good? Do I have to let a dog eat someone?