The City of Oakland has agreed to pay $4.5m to Scott Olsen, a marine corps veteran who was critically injured by city police during Occupy demonstrations, his attorneys announced on Friday.

Olsen, 26, sued the Oakland police department after being hit in the head by a police projectile during a chaotic October 2011 protest. He was admitted to a hospital in critical condition and suffered a fractured skull, broken neck vertebrae and brain swelling.

Soon after Olsen fell to the ground, a group of protesters gathered around him – they were soon hit with an explosive device that caused the group to scatter.

“It has been a very stressful experience, having to deal with it,” Olsen told Democracy Now! “For that reason alone, I’m happy it’s over.”

Olsen served two tours of Iraq and is a member of Iraq Veterans Against the War. He worked as a systems administrator when he was injured in the protest.

A city review board launched an investigation into the police department after the incident. “I think that having these lawsuits could be enough to bring some accountability to the police,” Olsen said.

City attorney Barbara Parker told the San Francisco Chronicle the city is paying Olsen $1.4m and the rest of the costs will be absorbed by the city’s insurance.

“Mr Olsen suffered a tragic injury that will affect him for the rest of his life,” Parker said. “This settlement will save the city the far greater costs of a trial and potentially much higher judgment. This is a fair settlement given the facts of the case and the significant injuries Mr Olsen sustained.”

Rachel Lederman, one of Olsen’s attorneys, said his legal team was relieved that he would get compensation for his injuries, but is calling on the mayor, city government and police chief to discontinue the use of "less lethal" munitions, like the beanbag that struck Olsen.

“No amount of money can really compensate Scott Olsen for losing part of his brain and the next time it may be even worse,” Lederman told the Guardian.

She said that as long as the police department has “less lethal” munitions, it will continue to use them to subdue protests.

“This is not really a happy day for us because it’s only a matter of time before we find ourselves back, or some other lawyers are back, with another multi-million dollar settlement coming from the Oakland taxpayers as the result of OPD misconduct or the use of these very dangerous so-called less lethal weapons on demonstrators."

Less-lethal weapons, also known as direct fired SIM, are not be used for crowd control in protests, according to an October 2013 OPD memo (pdf). “Direct Fired SIM may never be used indiscriminately against a crowd or group of persons even if some members of the crowd or group are violent or disruptive,” the memo states. However, these munitions may be used against “a specific individual.”

Oakland police did not respond to request for comment.