I hope UC Berkeley authorities will be able to announce some progress on the investigation soon. They have said that they are working "in close concert with the FBI on an ongoing investigation into the matter." But the same report indicates that the FBI has not confirmed or denied that it is actually conducting an investigation, and it is not immediately clear whether the FBI will find that the attack warrants federal attention.
Local failure to prosecute those who violently interfere with the rights of others -- because the locals have more sympathy with the thugs than those they attack -- is an old problem. Congress addressed it in the Ku Klux Act, signed by President Grant in 1871. This case will warrant federal attention if Berkeley police fail to act.
If two or more persons conspire to injure, oppress, threaten, or intimidate any person in any State, Territory, Commonwealth, Possession, or District in the free exercise or enjoyment of any right or privilege secured to him by the Constitution or laws of the United States, or because of his having so exercised the same; orFits like a glove. Multiple years in the federal slammer sounds about right. Maybe not ten.
If two or more persons go in disguise on the highway, or on the premises of another, with intent to prevent or hinder his free exercise or enjoyment of any right or privilege so secured--
They shall be fined under this title or imprisoned not more than ten years, or both; and if death results from the acts committed in violation of this section or if such acts include kidnapping or an attempt to kidnap, aggravated sexual abuse or an attempt to commit aggravated sexual abuse, or an attempt to kill, they shall be fined under this title or imprisoned for any term of years or for life, or both, or may be sentenced to death.
Most crimes of violence are state and local, not federal, matters, but there are exceptions. The KKK exception is an important one, and it should be invoked here if necessary.