It seems that Google searches do not aid in identifying murderers but once they have been identified Google searches certainly seem to help convict them.
>The cerebral Gundlach also gave investigators a tip for solving the crime. He says that while he was at home in his family room, it dawned on him that thieves would do a Google search using his grandmother’s name to find out more about the paintings and how much they might be worth... Gundlach told the authorities that they should check the Internet to see who might have googled the name Helen Fuchs. He says exactly two such searches were executed: one by him and one by the thieves.
That's just from a quick Google. I've heard of criminals becoming suspects from Googling crimes before they become public, it's not that hard to identify an early or frequent Googler in most cases especially if they are logged in.
