Videoing or photographing suspicious people


Could you advise on the guidelines re videoing &/or photographing, using a mobile phone, any suspicious persons? It could be helpful if these images could be passed to the police in conjunction with registering such sightings & obtaining a CAD reference...could it?

If the suspicious person has a child with him/her & the two can not reasonably be separated when capturing the adult's image, does this affect what images I can capture. If I am concerned that the accompanying child could be used to enhance the chances of "wrongdoing", perhaps acting as a lookout,  being a distraction, etc. how would this be reflected in the guidelines.

This is a recent example, reported to 101 & taken seriously; I left out distinguishing details:

Woman with smallish boy in tow. Constantly slowly walking up & down parade of small shops for a long time. Woman using mobile phone all the time. She enters several shops but does not buy or trade wtih any (it has not yet been established how many she entered in total). She does this for two consecutive days.

Thank you.