The Senate has backed a proposal that could lead to the issuing of Purple Hearts to victims of the Fort Hood massacre and an attack on a Little Rock recruiting station.

The proposed National Defense Authorization Act legislation included a section directing the service secretaries to review whether the Fort Hood and Little Rock victims rated the Purple Heart, the nation's oldest military award.

Under the bill, the secretaries would have to report back within six months and specifically address the question of whether the victims were "killed or wounded as a result of an act of an enemy of the United States," a requirement for the award of the Purple Heart.

Thirteen people, including a pregnant soldier, were killed and 32 were wounded in the Nov. 5, 2009, gun rampage by Maj. Nidal Malik Hasan, an Army psychiatrist, at Fort Hood, Texas.

On June 1, 2009, U.S. citizen Abdulhakim Mujahid Muhammad, who was born Carlos Leon Bledsoe, opened fire with a rifle on a recruiting station in Little Rock, Ark., killing Army Pvt. William Long and wounding Pvt. Quinton Ezeagwula.

The Pentagon previously has opposed moves to award the Purple Heart to the Fort Hood victims, saying such action could be used by defense lawyers to argue that Hasan had been denied a fair trial. Hasan's court-martial ended in August, and he was sentenced to death.

During Muhammad's civilian capital murder trial, he changed his plea to guilty and was given a life sentence.

The awarding of the Purple Hearts could depend on how the service secretaries defined an "enemy of the United States."

In the case of Hasan, he acknowledged that Anwar al-Awlaki, a leader of al-Qaida in the Arabian Peninsula killed by a U.S. drone strike in Yemen, was his "mentor." Muhammad told arresting officers that there's "a war going on against Muslims, and that's why I did it."