The casket of Army Sgt. La David Johnson is wheeled to a hearse in 2017 in Cooper City, Fla. (Joe Raedle/Getty Images)

Acting defense secretary Patrick Shanahan said Thursday that he has completed a review of the events surrounding an ambush in Niger in which four American soldiers were killed and that no additional officers will be punished for their roles in it.

Shanahan said in a statement that he is “satisfied that all findings, awards, and accountability actions were thorough and appropriate” in regard to the Oct. 4, 2017, attack.

“Tragically, four U.S. and four Nigerien soldiers lost their lives when they were attacked by a numerically superior, heavily armed force,” Shanahan said. “Irrespective of anything that precipitated the ambush, the men of Team Quallam fought valiantly and we will recognize that valor.”

Shanahan’s statement misspelled the team’s name, which was named after the Nigerien town of Ouallam.

The decision was greeted Thursday by the Gold Star families who lost loved ones with a mixture of frustration, confusion and disappointment. They also are frustrated that valor award recommendations for several of the soldiers have been downgraded by the Army.

Arnold Wright, the father of one of the soldiers, said in a phone interview that he is not satisfied that the military has held accountable all of the officers who ordered his son’s team into battle without adequate support. He and some of the other families received a briefing at Fort Bragg, N.C., on Wednesday, and he came away thinking that it is time for Congress to get involved.

“This has been torture,” Wright said. "They strung this along, and they’ve strung us along month after month after month. They’re not being forthcoming about how the information was handled at each level of the chain of the command.”

For months, the families have asked why a small team of soldiers was sent on a counterterrorism mission in Niger with no air support and little preparation, even though the team’s commander, Capt. Michael Perozeni, raised concerns about whether they were prepared.

“There was very little new in the brief that we received, but we appreciated their candor and willingness to discuss any questions we asked,” said Henry Black, whose son also was killed in the battle. “As I expressed to them, I was puzzled as to why the investigation didn’t really emphasize or accentuate that the team had vigorously opposed the mission they were sent on.”

The Americans killed were Staff Sgt. Jeremiah W. Johnson, Staff Sgt. Bryan C. Black, Staff Sgt. Dustin M. Wright and Sgt. La David Johnson. Black and Wright were Special Forces soldiers, and the other two Americans were conventional soldiers assigned to the same 3rd Special Forces Group team.

From left, Staff Sgt. Bryan C. Black, Staff Sgt. Jeremiah W. Johnson, Sgt. La David Johnson and Staff Sgt. Dustin M. Wright. (U.S. Army/AP)

The incident raised fresh concerns about how thin the U.S. military was spread in Africa, especially as it carried out missions in areas where there was a known militant presence.

A previously released military investigation found that Perozeni’s team had gone out on what was initially characterized as a routine reconnaissance mission but was diverted to search for Doundoun Cheffou, an Islamic State leader who U.S. officials believed may have been linked to the kidnapping of an American.

The Special Forces team, accompanied by Nigerien soldiers, was ambushed early in the morning outside the village of Tongo Tongo. The Americans initially thought the group of enemy forces was small but realized within minutes that nearly 100 militants armed with mortars, machine guns and rifles were involved.

Black, Wright and Jeremiah Johnson were killed in the ambush by advancing militants while returning fire, according to the investigation and video of the firefight that was previously released by militants.

La David Johnson fought back using an M240 machine gun and a sniper rifle, but he was separated from his unit and forced to flee on foot. He was alone when shot by advancing militants while returning fire, and his remains were recovered about 36 hours later by Nigerien villagers, U.S. investigators found.

Among those the military punished administratively were Air Force Maj. Gen. J. Marcus Hicks, who oversaw U.S. Special Operations troops in Africa at the time, and Lt. Col. David Painter, a battalion commander who was based in nearby Chad. Hicks retired, but Painter was allowed to continue his career and is due for a promotion, the families said.

Another officer involved in authorizing the mission, Col. Bradley Moses, was not disciplined.

Jeremiah “JW” Johnson, who shares a first name with his late son, said that he has not talked with media in the 20 months since the ambush but decided to do so Thursday after receiving the latest briefing from the Army.

“Do we need a congressional investigation? Perhaps that’s what it should have been to begin with," he said. "There are too many powerful people involved who can cover for each other.”

The elder Johnson said that he initially was told that his son and Bryan Black were to be nominated for a Silver Star, with La David Johnson considered for a Distinguished Service Cross and Dustin Wright up for either a Distinguished Service Cross or Medal of Honor. There are 57 minutes of video on a helmet camera that Jeremiah Johnson was wearing during the battle that document some their actions, his father said.

“Every single one of those awards have been downgraded,” he said, questioning whether it is because lower-level awards receive less media attention.

Arnold Wright also said that Army officials told him his son was recommended for the Medal of Honor, but will not receive it.

Army Lt. Col. Loren Bymer, a spokesman for Army Special Operations Command, said Thursday that nine U.S. soldiers will be decorated for valor in the battle.

“Despite the anger which we have seen conveyed from the families, they are still our priority to ensure we continue to take care of them to our utmost ability,” he said. “With regard to the tremendous acts of valor that we saw on October 4th, we want the American people to understand their service and sacrifice to their families, their nation and each other."

Shanahan’s decision stands in contrast to how his predecessor, Jim Mattis, appeared to handle the case.

The acting Pentagon chief told the House Armed Services Committee during a hearing in March that he had opened another review, with the goal of achieving “appropriate accountability.”

“I don’t know when that will be complete, but I have to assume that much of the work that’s been done to date can be used,” Shanahan said at the time.

Henry Black said Thursday that he first learned about Shanahan’s decision not from military officials, but from a news story published Tuesday. He said he does not want to see anyone else punished, but that the Army must realize the team should not have been ordered to continue its mission despite concerns raised by soldiers on the ground.

“The commander on the ground is the one whose opinion should carry weight," he said. "In this case, I think that Captain Perozeni made the right recommendation not to execute the mission.”

This story was updated on June 12, 2019.