One year after law enforcement officers in Texas and Louisiana were ambushed by gunmen who said they were retaliating to high profile fatal police shootings nationwide, critics of Black Lives Matter are still trying to pin responsibility on the movement.

In a new lawsuit filed on Friday, an unidentified Baton Rouge officer blamed DeRay Mckesson, Johnetta “Netta” Elzie and three other prominent Black Lives Matter leaders for inciting and encouraging violence at demonstrations across the country.

More specifically, it claims the movement and rhetoric of its leaders inspired a decorated ex-US Marine sergeant to unleash a torrent of bullets upon Baton Rouge police on 17 July 2016, leaving three officers dead and another three injured – including the plaintiff, identified only as Officer John Doe Smith in the lawsuit.

The officer, a 42-year-old father of two, who worked in law enforcement for 18 years, was left “permanently disabled” when bullets struck his abdomen, shoulder and head during the methodical ambush by 29-year-old Gavin Long at a convenience store.

Long, who was black, and was killed by police in a shoot-out, had written in a suicide note that his actions were a “necessary evil” intended to “create substantial change within America’s police force”. He said he felt compelled to “bring the same destruction that bad cops continue to inflict upon my people, upon bad cops as well as good cops in hopes that the good cops (which are the majority) will be able to stand together to enact justice and punishment against bad cops”.

The attack came 12 days after a different shooting in the same city, when a white Baton Rouge police officer shot and killed Alton Sterling, a 37-year-old black man, outside a convenience store. A day later, another black man, Philando Castile, was fatally shot during a traffic stop by a police officer in Falcon Heights, Minnesota.

Black Lives Matter protests erupted across the country, including a peaceful one on 7 July in downtown Dallas. But it turned deadly, too, when an army veteran, Micah Johnson, ambushed law enforcement officers who were overseeing the demonstration route. Five Dallas officers were killed and seven more were wounded.

Before he was killed in a stand off with police, Johnson told negotiators he was angry over the shootings in Louisiana and Minnesota and wanted to kill white police officers.

Ten days after Dallas, Long drove to Baton Rouge from Kansas City, Missouri, and continued the bloodshed on Sunday morning.

The new Baton Rouge lawsuit claims that Long’s ambush attack may not have happened if Black Lives Matter leaders had not incited violence among their followers, even though an exhaustive investigative report determined that Long had not attended any of the Black Lives Matter demonstrations in Baton Rouge after Sterling’s death and that he believed protests were a waste of time.

Mr Mckesson and his fellow activists were responsible for the unidentified officer’s injuries because they incited “disdain, hatred and violence against police” at protests, on social media and in news interviews, according to the lawsuit. It said Black Lives Matter “seized upon” the fatal police shooting of Sterling by a Baton Rouge police officer “to further incite its followers to take action against police”.

Local news outlets reported that the description of the officer’s injuries match those of East Baton Rouge sheriff’s deputy Nick Tullier, who nearly died in the shooting and remains hospitalised at a rehabilitation facility in Houston.

The officer has endured more than 16 abdominal surgeries and suffered extensive brain damage that has impacted his communication abilities, according to the lawsuit. He is still under constant threat of infection in his remaining wounds.

“While there is no way to know how far (the officer) will progress back to normal life, he is definitely permanently disabled,” the lawsuit says.

The complaint asks for at least $75,000 in damages.

“This is quite a world,” Mr Mckesson told Associated Press on Friday when he was made aware of the lawsuit. He later told CNN that he was “confident” the lawsuit “has no merit”. Ms Elzie declined to comment.

This lawsuit is the second to be filed against Mr Mckesson by a Baton Rouge police officer; both were filed by attorney Donna Grodner. In the previous lawsuit, Ms Grodner argued on behalf of another unnamed officer that Black Lives Matter and Mr Mckesson were responsible for injuries the officer sustained during protests that took place in Baton Rouge after Sterling’s death.

Mr Mckesson’s attorney asked a federal judge to throw out that lawsuit, arguing that Black Lives Matter is a social movement, not an organisation, and therefore cannot be sued. The judge has not yet decided whether to dismiss the case.

Mr Mckesson and other protesters arrested during the July demonstration in Baton Rouge last year later sued the city and local law enforcement agencies, but agreed to settled. Charges were never brought against 98 of the 190 people arrested at the protests, including Mr Mckesson.

Police officers shot in Baton Rouge Show all 21 1 /21 Police officers shot in Baton Rouge Police officers shot in Baton Rouge Baton Rouge Police officers patrol Airline Hwy Getty Images Police officers shot in Baton Rouge A law enforcement helicopter is seen near the scene where police officers were shot in Baton Rouge REUTERS Police officers shot in Baton Rouge A Baton Rouge Police officers patrol pours water on his head on Airline Hwy Getty Images Police officers shot in Baton Rouge East Baton Rouge Police officers patrol Airline Hwy Getty Images Police officers shot in Baton Rouge President Obama speaks at a press conference in the Brady Press Briefing Room at the White House in Washington. Obama remarked on the shooting in Baton Rouge, Louisiana in which three officers were killed and three more wounded by armed suspects Getty Police officers shot in Baton Rouge Police officers block off Airline Highway near the scene of a fatal shooting of police officers in Baton Rouge REUTERS Police officers shot in Baton Rouge Baton Rouge Police officers patrol Airline Hwy Getty Images Police officers shot in Baton Rouge A police helicopter flies near the scene of a fatal shooting of police officers in Baton Rouge REUTERS Police officers shot in Baton Rouge East Baton Rouge Police officers patrol Airline Hwy Getty Images Police officers shot in Baton Rouge Police officers block off a road after a shooting of police in Baton Rouge REUTERS Police officers shot in Baton Rouge Police officers block off Airline Highway near the scene of a fatal shooting of police officers in Baton Rouge REUTERS Police officers shot in Baton Rouge A law enforcement helicopter is seen near the scene where police officers were shot in Baton Rouge REUTERS Police officers shot in Baton Rouge Law enforcement vehicles block access to Airline Highway REUTERS Police officers shot in Baton Rouge A police helicopter flies near the scene of a fatal shooting of police officers in Baton Rouge REUTERS Police officers shot in Baton Rouge Police officers block off a road near the site of a shooting of police in Baton Rouge REUTERS Police officers shot in Baton Rouge Police officers block off a road near the site of a shooting of police in Baton Rouge REUTERS Police officers shot in Baton Rouge Police officers arrive near the site of a shooting of police in Baton Rouge REUTERS Police officers shot in Baton Rouge Police officers block off a road after a shooting of police in Baton Rouge REUTERS Police officers shot in Baton Rouge Police officers block off a road after a shooting of police in Baton Rouge REUTERS Police officers shot in Baton Rouge Police officers block off a road after a shooting of police in Baton Rouge REUTERS Police officers shot in Baton Rouge Authorities talk to the driver of a car near an area where several officers were shot while on duty less than a mile from police headquarters AP

On Sunday, another lawsuit was filed against Baton Rouge and Louisiana law enforcement agencies on behalf of 13 protesters and two reporters arrested during the demonstrations, alleging excessive use of force and civil rights violations, BuzzFeed News reported.

David Roland, the director of litigation at the Freedom Centre of Missouri, told PBS News Hour that he was concerned civil lawsuits blaming Black Lives Matter and its leaders for the actions of individuals loosely affiliated – if affiliated at all – with the movement could threaten the first amendment.

“It’s easier to dissuade protests, to chill speech, using the threat of a civil suit at least in some ways,” Roland told PBS. “It can’t result in someone going to jail, but it can result in them being bankrupt.”