Four of them were arrested, but they could "not find the evidence that they were responsible for the crime", and that once the police could not tie the suspects to the event the case was closed.
They said that if more evidence came to light, there was a possibility of reopening the case.
Thamam al-Nawaja, a 58 year-old Palestinian woman, along with her 70 year-old husband, and one of her nephews, were herding their flocks when they were badly beaten by four masked men wielding baseball bats.
The incident took place in the south of the West Bank near the Susia settlement.
The attack was filmed by a relative, who had been given a camera by the human rights group B'Tselem as part of its Shooting Back project.
B'Tselem had handed video cameras to Palestinians in troubled areas so that they could document abuses against them.
Mrs Nawaja told the Israeli newspaper Haaretz that she couldn't understand how the police did not catch the men who beat her.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.