WASHINGTON (AP) — In a stinging rebuke of the military's efforts to curb sexual assault, members of a Senate panel hammered Defense Department officials on Wednesday for making too little progress in combating the crimes and failing to improve a military justice system that victims described as slow and uncaring.

During a two-part hearing, the panel heard harrowing testimony from several victims, who said military justice is broken and pushed for Congress to take action to stem the rape, sexual assault and sexual harassment that they said are pervasive in all the service branches.

Pentagon officials said they are taking the problem seriously. "Sexual assault in the military is not only an abhorrent crime that does enormous harm to the victim, but it is also a virulent attack on the discipline and good order on which military cohesion depends," said Robert Taylor, the Pentagon's acting general counsel.

"The Air Force has zero tolerance for this offense," added Lt. Gen. Richard Harding, the judge advocate general of the Air Force.

But lawmakers pointed to a decision by an Air Force general to reverse a guilty verdict in a sexual assault case as evidence of how the military fails the victims who come forward to report the crimes. Under military law, a commander who convenes a court-martial is known as the convening authority and has the sole discretion to reduce or set aside guilty verdicts and sentences or to reverse a jury's verdict.

Her voice rising, Sen. Kirsten Gillibrand, D-N.Y., said all the training and all the promises of "zero tolerance" from the witnesses amounted to nothing if a convening authority is the only individual who can decide whether to overturn a case. Gillibrand is the chairwoman of the Senate Armed Services personnel subcommittee.

"I appreciate the work you're doing, but it's not enough," she told the military officers arrayed at a long witness table.

Rebekah Havrilla, a former Army sergeant, told the panel that she encountered a "broken" military criminal justice system after she was raped by another service member while serving in Afghanistan. Havrilla described suffering from post-traumatic stress disorder and described how her case was eventually closed after senior commanders decided not to pursue charges.

"What we need is a military with a fair and impartial criminal justice system, one that is run by professional and legal experts, not unit commanders," Havrilla said.

BriGette McCoy, a former Army specialist and a Persian Gulf war veteran, said she was raped when she was 18 and at her first duty station. But she did not report it. Three years later, she reported being sexually harassed and asked for an apology and to be removed from working directly with the offender.

"They did remove me from his team and his formal apology consisted of him driving by me on base and saying 'sorry' out of his open car door window," McCoy told the subcommittee.

Defense Secretary Chuck Hagel has ordered a review of Air Force Lt. Gen. Craig Franklin's decision to overturn the sexual assault conviction against Lt. Col. James Wilkerson, a former inspector general at Aviano Air Base in Italy.

The case is generating support for legislation that would prevent commanding officers from overturning rulings made by judges and juries at courts-martial proceedings.

"It appears to me that the Aviano general has really failed," said Sen. Claire McCaskill, D-Mo., referring to Franklin.

Anu Bhagwati of the Service Women's Action Network told the panel that commanders are unable to make impartial decisions because they usually have a professional relationship with the accused and, often times, with the victim as well. Bhagwati, a former Marine Corps captain, said court-martial cases should be left in the hands of "trained, professional, disinterested prosecutors."

Gillibrand called the Wilkerson case "shocking" and promised to take a hard look at the military justice system. Nearly 2,500 sexual violence cases in the military services were reported in 2011, but only 240 made it to trial, Gillibrand said.

Wilkerson was found guilty on Nov. 2 by a jury of military officers on charges of abusive sexual contact, aggravated sexual assault and three instances of conduct unbecoming of an officer and a gentleman. The victim was a civilian employee. Wilkerson was sentenced to a year in prison and dismissal from the service.

Wilkerson was at the U.S. Naval Consolidated Brig in Charleston, S.C., until Feb. 26, when Franklin exercised his discretion as the convening authority. Franklin reviewed the case over a three-week period and concluded "that the entire body of evidence was insufficient to meet the burden of proof beyond a reasonable doubt," Hagel wrote in a March 7 letter to Sen. Barbara Boxer, D-Calif.

But Hagel told Boxer neither he nor the Air Force secretary is empowered to overrule Franklin, who is the commander of the 3rd Air Force at Ramstein Air Base in Germany.

Boxer said during testimony before the subcommittee that "immediate steps must be taken to prevent senior commanders from having the ability to unilaterally overturn a decision or sentence by a military court."

Taylor, the acting general counsel, said in his written testimony the Defense Department is examining the role the convening authority plays, including a commander's power to set aside a court-martial's findings. But Taylor also stressed that commanders have long held this authority and it is directly tied to the need for the "portability" of military justice throughout the world and the need for senior officers to maintain discipline in the ranks.

In the wake of Franklin's decision, Reps. Jackie Speier, D-Calif., Bruce Braley, D-Iowa, and Patrick Meehan, R-Pa., introduced legislation Tuesday in the House that would strip military commanders of the power to overturn legal decisions or lessen sentences. Their bill would amend the Uniform Code of Military Justice to take away the power of a convening authority to dismiss, commute, lessen or order a rehearing after a panel or judge has found the accused guilty and rendered a punishment.

McCaskill plans to introduce legislation that would change the Uniform Code of Military Justice by preventing a convening authority from overturning a decision reached by a jury. The legislation also would require the convening authority to issue a written justification for any action.

"This is not a crime that we're going to train our way out of," said McCaskill, who emphasized the need for the strong and effective prosecution of offenders.

Brian Lewis, a former Navy petty officer, told the subcommittee not to forget that many victims of sexual assault and harassment in the military are male. Lewis said he was raped in 2000 by a non-commissioned officer who outranked him. His commanders ordered him not to report the crime to Naval Criminal Investigative Service. Lewis said he was later misdiagnosed with having a personality disorder and he was discharged from the service in 2001.

"I carry my discharge as an official and permanent symbol of shame, on top of the trauma of the physical attack, the retaliation and its aftermath," Lewis said.

Sen. Angus King, I-Maine, asked whether the culture would change if the laws were overhauled. Lewis described the limitations of military law, arguing that it was unconscionable that punishment is solely at the discretion of a single individual and the offense of sexual assault is merely a year in prison.

"The military does not value what happened to the victim," Lewis said.