Stay alert to odd encounters

This from a resident near Fairmont Park after seeing the break-in reports:

A few days before I read about the first warning of breakins in the area something odd happened at my door.
In the afternoon a young man, slim, slightly red-blond hair, about 18 or so rang the bell and asked politely if he could have a glass of water.
I told him that I felt a bit uncomfortable about this rather strange request but I obliged, locked the front door with him standing on the front porch and returned with the glass of water. He drank 2/3 of it. I asked him why he was thirsty and he said he had been running. I should have said..but you don't seem to be sweating very much..but I did not. Another young man, dark haired, slim and about the same age stood in the driveway texting on his phone during this episode and said nothing.
This could have been an attempt to find out if anyone was home.