The hearing ended, updated story below:
(CNN) -- Chiefs of every military branch told a Senate committee Tuesday they opposed letting prosecutors, rather than commanders, handle sexual assault investigations, as one senator has introduced legislation aimed at doing just that.
Senate Armed Services Committee Chairman Carl Levin said there may be public confusion about the military's reporting process.
Referring to media reports that there is only one way to report sexual assault, the Michigan Democrat asked each of the military heads at a hearing if there currently are multiple options in addition to notifying a unit commander. They replied yes.
They also told the committee that instances of commanders ignoring their judge advocate generals' advice in sexual assault cases are extremely rare.
Sen. James Inhofe, the top Republican member of the Armed Services Committee, earlier called sexual assault in the military "an enemy to morale and readiness" and urged his colleagues to tread carefully in tackling the issue.
Inhofe said he is opposed to any legislation "removing commanders from their indispensable roles" in the military justice system and noted that military and civilian courts are different animals because members of the military do not enjoy the same rights as civilians.
"There's a risk of unintended consequences if we act with haste without thorough and thoughtful review," the Oklahoma lawmaker said.
The congressional committee called the unprecedented hearing, which includes testimony from the Joint Chiefs of Staff and top military lawyers, after Sen. Kirsten Gillibrand, D-New York, introduced legislation that would remove the chain of command from the process victims go through to get their claims heard
Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff; Gen. Raymond Odierno, chief of staff of the Army; Adm. Jonathan Greenert, chief of Naval operations; Gen. James Amos, commandant of the Marine Corps; Gen. Mark Welsh, chief of staff of the Air Force, and Adm. Robert Papp Jr., commandant of the Coast Guard, each acknowledged that sexual assault is a serious problem but one that commanders are equipped to handle.
They all used their opening statements to the committee to express opposition to Gillibrand's proposal.
"These crimes cut to the heart of the Army's readiness for war. They destroy the very fabric of our force -- soldier and unit morale," Odierno said.
But while there may be derelict commanders, he said, those are anomalous, and the chain of command must be "fully engaged and at the center of any solution" to the issue.
The general later said that it was a misconception that commanders handle complaints independently of the military justice system.
"You have a very experienced judge advocate by your side the whole time," he said. "They are taught to rely on their judge advocate generals."
Gillibrand was undaunted, emphasizing that commanders would be removed from the process only for the most serious crimes, such as rape and murder.
She said she agreed with the military chiefs that "the chain of command is essential for setting the climate," but there is a difference between setting a tone and dealing with serious crime, especially when one of the compounding factors in reporting sexual assault is a lack of trust.
"They fear retaliation. They fear being blamed," Gillibrand said of the victims. "That is our biggest challenge right there."
Sen. Tim Kaine, D-Virginia, said 90% of victims who don't report said they didn't do so out of fear of retaliation or because they were deterred after witnessing the treatment of other victims who reported sexual assaults.
Gillibrand said there are commanders who are not objective, who don't want women in the military in the first place, who don't know the difference between a "slap on the ass and rape."
Sens. Lindsey Graham, R-South Carolina; and Claire McCaskill, D-Missouri, also previously expressed concerns about the military lumping all sexual assault and sexual harassment cases under the category of unwanted sexual contact, rather than breaking out the more severe crimes of rape, sodomy and assault.
Gillibrand added that the United States should follow the leads of allies like Israel, Australia and the United Kingdom, all of which, she said, have taken the chain of command out of investigations into serious crimes.
Dempsey replied that he'd prefer a "constellation of checks and balances" to help empower commanders and hold them accountable. Amos said he'd be open to removing the chain of command if he thought it would work, but he had no proof it would.
A second panel of military commanders, convened after the military chiefs, followed suit with their superiors, saying not only would removing commanders from the investigative process undermine their troops' trust in them, but it would also deny them the effective tool of nonjudicial punishment, known as Article 15.
Commanders must also be able to decide whether an allegation should