BISMARCK, N.D. — A New York woman who suffered a serious arm injury while protesting the Dakota Access pipeline in North Dakota is preparing for her fifth surgery, even while she’s still under investigation.

Sophia Wilansky was injured in an explosion during a violent clash between protesters and police last November. Protesters allege the blast was caused by a concussion grenade thrown by officers. Police maintain it was caused by a propane canister protesters rigged to explode.

Recently unsealed court documents indicate the government last spring sought evidence that might implicate Wilansky by searching her Facebook account. Eight months later, no charges have been filed against her. Federal authorities say the investigation is ongoing.

Wilansky’s father says she has limited use of her left arm and hand. She’s scheduled for another surgery Dec. 12.