WASHINGTON (AP) - Outrage over an Air Force officer's decision to overturn a jury's guilty verdict in a sexual assault case has Republicans and Democrats joining forces on ambitious legislation to change the military justice system. On both sides of the Capitol, lawmakers have interpreted Defense Secretary Chuck Hagel's recent proposal to essentially strip commanding officers of their ability to reverse criminal convictions of service members as an opening to revise the decades-old Uniform Code of Military Justice. Congress repeatedly has challenged the military's lack of resolve in fighting sexual assault in its ranks, an offense considered far more prevalent than the reported cases of 3,192 in 2011, the most recent figure available. Former Defense Secretary Leon Panetta said that because so few victims report the crime, the real number is closer to 19,000 assaults. Hagel acknowledged the problem earlier this month in announcing his proposal to eliminate the discretion of a commanding officer to reverse a court martial ruling, except for minor offenses, and to require a commanding officer to explain in writing any changes that are made. The crime of sexual assault in the ranks "is damaging this institution. There are thousands of victims in the department, male and female, whose lives and careers have been upended, and that is unacceptable," the secretary said. A single case has set off a recent outcry in Congress. Lt. Col. James Wilkerson, a former inspector general at Aviano Air Base in Italy, was found guilty last year of charges of abusive sexual contact, aggravated sexual assault and three instances of conduct unbecoming of an officer and a gentleman. The incident involved a female contractor. Wilkerson was sentenced to a year in prison and dismissal from the service, but Lt. Gen. Craig Franklin, commander of the 3rd Air Force at Ramstein Air Base in Germany, reviewed the case and overturned the jury's verdict of guilty. Franklin explained in a six-page letter to the Air Force secretary that he found Wilkerson and his wife more believable than the alleged victim. The ability of a commanding officer to reverse a jury verdict creates a single impression for victims of sexual assault in the military, Sen. Claire McCaskill, D-Mo., told senior officers at a congressional hearing last week. Those women think "no matter what happens at the trial, no matter if they believe me, some general is going to decide I'm a slut," McCaskill said, capturing the frustration and anger over the case. In the slow-moving Congress, lawmakers are quickly writing legislation to change the Uniform Code of Military Justice, which was established in 1950 and was revised in 1968 and 1983. Separate measures in the House and Senate are expected to become provisions in annual defense policy bills, one of the few pieces of legislation that Congress passes every year. The Armed Services committees are expected to complete the bills in June. Sen. Kirsten Gillibrand, D-N.Y., the new chairwoman of the Senate Armed Services personnel subcommittee, is working with members in both parties on legislation to give Judge Advocate General prosecutors the discretion on whether to go to trial, and to largely strip commanding officers of the ability to toss out a verdict. "Our goal would be to remove all decision-making out of the chain of command about whether to prosecute a case and whether to bring a case to the chain of command," Gillibrand said in a recent interview. And it would not just be for sexual assault. We're looking at all violent crimes. Commanding officers would retain their current authority in cases that are the equivalent of misdemeanors in the civilian courts under her measure. And under Hagel's proposal, members of the military who are convicted could still appeal. Gillibrand said she also has been in contact with Defense Department lawyers, insisting that collaboration with the Pentagon is vital to ensuring that Congress gets the legislation right. Everyone knows the current system is not working. Everyone knows that 19,000 sexual assaults and rapes a year is unacceptable," she said. I think the military has been trying to grasp this for a while now without success and so they may need some outside assistance in looking at it freshly. ... It's not one of those situations where they can say, 'We got this,' because they clearly don't. In the House, Reps. Mike Turner, R-Ohio, and Niki Tsongas, D-Mass., who have collaborated in the past on legislation to help sexual assault victims in the military, are again writing legislation to address the issue. This time, Turner said the focus is on reining in the power of commanding officers to ensure they cannot set aside a conviction for sexual assault. Each year that we have advanced remedies to try to affect sexual assault in the military, we found something unique and egregious was in the Defense Department system that would re-victimize victims of sexual assault. The case of Gen. Franklin setting aside the sexual assault is absolutely one of those," Turner said in an interview. "When we've talked to representatives at the Pentagon, they've indicated that they in no way ever foresaw that someone would supplant their opinion for that of a tribunal," he said. Turner's aggressive effort on the issue stems in part from the brutal death of Lance Cpl. Maria Lauterbach, 20, of Vandalia, Ohio, whose charred remains were found in the backyard of the North Carolina home of a former Marine corporal in January 2008. Lauterbach had accused Cesar Laurean of rape and of being the father of her unborn baby. The two were assigned to the same unit at the Camp Lejeune Marine base. A jury convicted Laurean of murder in the death of his pregnant colleague and he was sentenced to life in prison in August 2010. The tragedy of the Maria Lauterbach case is the military knew she'd been subject to sexual assault, left her with the accused, told both of them that as soon as her baby was born that they would do DNA testing and then prosecute him. And then he murdered her and buried her to eliminate the evidence," Turner said. It's just outrageous to think that she could be left in such a vulnerable position that resulted in her death.