The Justice Ministry declared Sunday that no indictments will be filed against police in the case of a US activist who was hit by a tear gas canister and left comatose during a violent demonstration in the West Bank last year.Tristan Anderson, 38, of Oakland, California, was critically injured during a Palestinian protest in the West Bank village of Nil'in last March. Amir Moran, spokesman for Tel Hashomer hospital, where Anderson is being treated, said his condition "has not changed."Justice Ministry spokesman Ron Roman said the investigation determined there was no criminal intent in harming Anderson. The investigation was opened in May and closed several weeks ago, but results were made public only Sunday.Human rights groups charge Anderson's case highlights a culture of impunity toward Israeli forces, because incidents of harm against Palestinians and their supporters are rarely investigated and few reach prosecution."The number of civilians harmed and injured and then the number ofinvestigations — a small minority of cases, and a tiny number ofprosecutions — point to a very, very clear picture of impunity," saidSarit Michaeli of rights group B'Tselem.There were around 400 protesters at the demonstration where Andersonwas injured, the IDF said at the time. Some of them threw rocks attroops, who used riot gear to quell the unrest, the army added, withoutelaborating.Anderson's family was not immediately available for comment. Israel has said its forces were responding to attacks by violentdemonstrators who were ignoring an order declaring the area anoff-limits closed military zone. Such clashes are a weekly Friday eventin several places along the Israeli separation barrier, as Palestiniansand their backers gather to confront IDF troops.