The trial of an elite US Navy Seal accused of shooting unarmed civilians and stabbing a teenage captive to death in Iraq began on Monday at a military court in California. Special Operations Chief Edward Gallagher, 40, is charged with several war crimes including premeditated murder, attempted murder of two civilians – including a young girl – with his sniper rifle and obstruction of justice. His alleged acts in Iraq in 2017 were reported by men under his own command in the special operations branch of the US Navy. They were among American troops deployed to Mosul, in northern Iraq, alongside Iraqi forces battling ISIS for control of the city. Mr Gallagher, a decorated veteran of combat missions in Iraq and Afghanistan, faces life imprisonment if convicted by the San Diego court. He denies all the charges against him. His lawyers claim he is the victim of a "cabal" who plotted against him in order to remove him from the platoon. Seven Marines, four sailors and a Navy Seal were questioned on Monday during jury selection. Most served in conflicts in Iraq and Afghanistan. Each said they thought it possible that Navy Seals could lie or make false allegations. A jury is likely to be seated on Tuesday. The lead prosecutor was removed from the case earlier this month for tracking the defence team's emails. According to statements read at a preliminary hearing last year, some members of the "Alpha" platoon were so horrified by Mr Gallagher's behaviour that they tampered with his sniper rifle and fired warning shots to scare civilians away before he had time to open fire on them. They told investigators that Mr Gallagher would brag about the number of people he had killed, according to <em>The New York Times</em>. In May 2017, Iraqi forces captured an injured ISIS combatant who appeared to be about 15 years old. According to the testimony of two Seals, Mr Gallagher approached while a doctor was treating the young man and stabbed the prisoner several times in the neck and chest with a hunting knife. A few minutes later Mr Gallagher and his commanding officer allegedly instructed members of the platoon to pose for a photo around the body as if it were a trophy. Mr Gallagher's case has proven divisive in the US, where he remains a war hero to some. His cause has been championed by about 40 Republican members of Congress, as well as the right-wing Fox News channel. President Donald Trump last month expressed concern over the prosecution of US soldiers accused of war crimes, with Mr Gallagher reportedly among those he is considering granting pardons.