SAN DIEGO — Navy Special Operations Chief Edward Gallagher was found not guilty on Tuesday of first-degree murder of a captive fighter and attempted murder of civilians in Iraq, but was convicted of a single charge for posing with the dead body of an Islamic State captive.
Gallagher, 40, a decorated eight-tour veteran serving in SEAL Team 7, became a rallying cause of some Republicans in Congress and members of the conservative media, and the focus of a potential pardon by President Trump.
Because the maximum sentence he could face was four months and he has spent more time than that in pretrial confinement, he will go free.
The chief was turned in by his own platoon last spring. Several fellow SEALs reported that their leader had shot civilians and had killed a captive Islamic State fighter with a custom hunting knife during a deployment in Iraq in 2017. He was also charged with obstruction of justice by threatening to kill SEALs who reported him.
A jury of seasoned combat veterans asked for review of testimony Tuesday. The panel sought the testimony of Lieutenant Thomas MacNeil, the first of nearly a dozen SEALs who testified at the court-martial.
MacNeil, a former roommate of Gallagher, identified the defendant’s special knife and described hearing a radio transmission that an airstrike in support of Iraqi forces had wounded an Islamic State fighter.
‘‘I heard Chief Gallagher announce, ‘Lay off, he’s mine,’ ’’ MacNeil said.
MacNeil was not one of the two SEALs who said they saw Gallagher stab the prisoner, but he acknowledged posing for photographs with the corpse.
The jury began deliberating Monday after closing arguments in which both sides told jurors that witnesses had lied on the stand.
The panel weighed whether Gallagher, a 19-year veteran on his eighth deployment, went off the rails and fatally stabbed the war prisoner on May 3, 2017, as a kind of trophy kill, or was the victim of allegations fabricated after the platoon returned to San Diego to stop him from getting a Silver Star and being promoted.
A military prosecutor asserted the proof of Gallagher’s guilt is his own words, his own photos, and the testimony of his fellow troops, while defense lawyers called the case a ‘‘mutiny’’ by entitled, junior SEALs trying to oust a demanding chief.
The jury is made up of five Marines and two sailors, including a SEAL, many of whom had been in combat in Iraq.
Defense lawyer Marc Mukasey said Tuesday that he expected a quick verdict, given the makeup of the jurors and the looming Fourth of July holiday.
‘‘Everybody wants to celebrate the holiday, right?’’ said Mukasey wearing a big smile, a charcoal suit and ‘‘Free Eddie’’ baseball cap emblazoned with the American Flag.
During the two-week trial Special Operator Corey Scott, a medic like Gallagher, told the court that he saw the chief stab the Islamic State militant in the neck but stunned the court when he said he was the one who ultimately killed the prisoner by plugging his breathing tube with his thumb as an act of mercy.
Seven SEALs said Gallagher unexpectedly stabbed the prisoner moments after he and the other medics treated the detainee. Two, including Scott, testified they saw Gallagher plunge his knife into the prisoner’s neck.
Under the military justice system, the prosecution needs two-thirds of the jury, or in this case five jurors, to agree to a guilty verdict to convict. Jurors can also convict him of lesser charges or acquit him.
Navy Commander Jeff Pietrzyk said in closing arguments that text messages by Gallagher show he is guilty.
One message said: ‘‘I’ve got a cool story for you when I get back. I’ve got my knife skills on.’’ Another text stated: ‘‘Good story behind this. Got him with my hunting knife.’’
He then showed a photo of the dead prisoner with Gallagher holding up his head by the hair.
‘‘The government’s evidence in this case is Chief Gallagher’s words, Chief Gallagher’s pictures, Chief Gallagher’s SEALs,’’ Pietrzyk said.
The prosecutor acknowledged that the victim — a 17-year-old Islamic State fighter wounded in an airstrike — is not sympathetic.
‘‘We’re not ISIS. When we capture someone and they’re out of the fight, that’s it. That’s where the line is drawn,’’ Pietrzyk said.
During the trial, it was revealed that nearly all the platoon members readily posed for photos with the dead prisoner and watched as Gallagher read his reenlistment oath near the body in an impromptu ceremony.
Another defense lawyer, Tim Parlatore, began his closing argument the same way he started the trial. ‘‘This is case is not about murder, it’s about mutiny,’’ Parlatore said.
The attorney said there’s no body, no forensics, and the SEALs who testified against Gallagher lied because they didn’t like his demanding leadership. He called the pictures of Gallagher clutching the corpse’s hair and his texts about his knife skills just the dark humor of a warrior.
Parlatore also contended that investigators never asked Scott about the cause of the death, which is why they were surprised by his testimony.
Gallagher’s attorneys said there are a number of things that could have caused the militant’s death.