Uprooted trees are gold mines for people interested in finding objects like arrowheads or other historic artifacts.

It's a natural time capsule. The ground under the tree is stabilized for the duration of the tree's life, effectively snapshotting its contents.

The first time someone explained this to me while on a hike, as they excitedly dug through a mess of exposed tree roots, was one of those rare, surreal perspective-shifting moments. Suddenly I saw the forest surrounding me as a versioned filesystem of sorts, with every tree holding a snapshot of ground for its respective age beneath.

“Police in Connecticut say that a tree overturned by hurricane Sandy has revealed a skeleton buried beneath that may have been there since colonial times.

‘Yes,’ said the home’s owner, ‘colonial times...’”

-Weekend Update, Saturday Night Live, December 1, 2012

http://decoy.tvpassport.com/talk/late-laughs-week-november-2...

And how the heck can they determine a 1000 year old skeleton is a murder victim?

Not sure if you are asking in earnest, but bone damage from a knife would suggest the skeleton was from a murder victim.

They can tell skeletons significantly older than 1000 years were from someone, for example, killed by a tiger, due to teeth marks on bones.

Saw an interesting viking museum in Norway that had a skeleton of a man who had his leg shorn off by an axe in battle. That one may be a bit more obvious I suppose, but I suspect there's a ton you can learn from just a set of bones.

You could probably make a tv show about that, maybe call it bones :-)

Blade markings on the bones, rib cage I believe. They were also able to say the victim was 17-20 years old

Maybe as people who were not murdered were buried in some sort of burial site? (Like a cemetery).

Most likely bone fractures and similar signs should still be visible.