At authenticateidentities.com in an article sub-titled How to Accurately Check a Photo ID, it reports on Face Comparisons in relation to comparing a facial image in a document but it is as relevant in relation to researching any person online, as your research may locate images of them online and you should understand the basics of what to lookout for when comparing facial images of people.
Facial Recognition / Image Comparison Sites
AWS requires an account, whilst some of the others are not brilliant but better than nothing.
Making Someone Look Older In A Photograph (not great but might help)