If your photos were taken from a public place (not private land) you can take as many as you want usually without restriction. You should however be careful of sensitive locations based on the world we live in now. Also you should never delete any pictures. If the Police are ever involved, your pictures are your evidence of events.
If you search for "Taking photos in a public place" there is a very good Tech Radar article with a section about security guards. It mentions that they cannot make you delete any pictures and if they do they could be committing a crime.