How to delete video from photos on iPhone 4S when no trash icon (or edit) is present?

My husband's iPhone 4s has lots of duplicates (and some triplicates) of videos that he would like to remove from the camera roll photo section. The duplicated (or triplicated) versions of the videos do not show a trash icon in the lower right corner and do not show an edit option either. These are all videos that he took using his iPhone. They don't show up in the video app.