In this file photo from Feb. 25, 2013, female Marine recruits prepare to fire on the rifle range during boot camp at MCRD Parris Island, South Carolina. Scott Olson/Getty Images

The Senate spent more than five hours Wednesday debating two amendments that would change the way the decades-old military justice system polices the epidemic of sexual assaults in the U.S. military as part of a $625 billion defense bill that establishes military policy. The bill, known as the National Defense Authorization Act, stalled in the chamber as Democrats and Republicans struggled over how to move ahead on the massive measure. Female members of the Senate took the lead in an impassioned debate over the issue, agreeing that the prevalence of sexual assaults in the armed services was unacceptable, praising the 26 changes to the military justice system already in the defense bill, but strongly disagreeing about how to prosecute the crimes. At issue are two different amendments put forward by Sen. Kirsten Gillibrand, D-N.Y., and Sen. Claire McCaskill, D-Mo.

Gillibrand's plan

Gillibrand proposed taking the decision to prosecute attackers accused of rape and sexual assault from commanders and giving it to seasoned military lawyers who hold the rank of colonel or higher. The top echelon of the military has opposed her plan and she has faced resistance from a number of Democrats and Republicans, including the chairman of the Armed Services Committee, Sen. Carl Levin, D-Mich. Gillibrand has the public backing of 53 senators, including Reid, Sen. Dick Durbin, D-Ill., and conservative Sens. Rand Paul, R-Ky., and Ted Cruz, R-Texas. However, she faces a 60-vote threshold for her measure to pass. Gillibrand described in explicit terms several horrific assaults only made worse by the military's handling of the cases. Quoting the words of a female marine who was raped in 2003, Gillibrand told the Senate, "Having someone in your direct chain of command doesn't make any sense, it's like getting raped by your brother and having your dad decide the case." The senator said Congress should establish impartial, objective consideration of evidence by trained military prosecutors. The Pentagon estimates 26,000 military members may have been sexually assaulted last year, based on an anonymous survey. Thousands of victims were unwilling to come forward despite new oversight and assistance programs aimed at curbing the crimes, the Pentagon said. Displaying a chart in the Senate chamber, Gillibrand said only 302 of the 3,374 reported cases last year have gone to trial. "The current system oriented around the chain of command has been producing horrible results," she said.

'Commanders must be involved'