There's an definitive way to answer - veins. Each one of us has unique veins and they are like a thumbprint. Unfortunately my photoshop skills were too limited to pull the veins out of these photos. Can you do better? Plan B - notice the thumbs, the shape, the thumbnails and so on. Looks like a match to me. However if the veins match, that would be conclusive. On the negative, there appears to be less armhair on JFK Jr. If someone has a high res older photo of JFK Jr hands and arms, that'd help. Even better if someone can match the veins…
Thanks for including my 'notice the thumbs' graphic. to make it conclusive we need a old high res photo. this will accomplish two things:
A) we can match arm hair and thumbs more accurately.
B) if somebody can take the old high res image and photoshop the veins to stand out. each human has a unique circulatory system and the veins are like a fingerprint - being unique to each person. If the (arm/hand) veins match then WE WILL KNOW 100% it is JFK Jr!