WASHINGTON (CNN) -

The sometimes violent protests in Ferguson, Missouri, and the law enforcement response has sparked a debate about what some call the "militarization of police," after armored vehicles, stun grenades and high-tech weaponry were brought in to calm the violence.

Some of the equipment may be military surplus that came from the federal government through a program from the Defense Department's Defense Logistics Agency, which provides military equipment to local police departments across the country.

The DLA's law enforcement support program was created in 1999. "This is a program legislated by Congress which allows the secretary to transfer some excess military property to local law enforcements," said Pentagon spokesman Rear Adm. John Kirby on Tuesday.

Kirby said since 2007 the Ferguson Police Department has received two Humvees, one generator, and one cargo trailer. Over the same time period, the St. Louis County Police Department received six pistols, 12 rifles, 15 weapon sites, an explosives disposal robot, three helicopters, seven Humvees (two used by Ferguson Police), and two night-vision devices.

"It's still up to local law enforcement to determine how and when and where and under what circumstances they use excess military equipment," said Kirby, but Defense Secretary Chuck Hagel "has been mindful of the public debate and discussion about this issue and asked his staff this morning about some additional information about this program."

According to Kirby, Hagel has received an information paper with more details on the program, but has yet to order a formal review. Hagel wants a better understanding of the law and regulations governing the transfer program and what parts of that program are the responsibility of the Defense Department.

The program has been in place for several years with little controversy and attention, but has grabbed the national spotlight with the unrest in Ferguson, where police have used what looks like tactical military gear and vehicles, although it's not clear what equipment may have actually come from Pentagon inventories.

Pentagon officials say a key issue for the department is the fact that once the equipment is transferred, the military has no control over how a local agency uses it.

Many police departments also get funding for military-style equipment from Homeland Security and the Justice Department, which operate programs aimed at beefing up police capability in the event of a terrorist attack.

President Barack Obama called for a review of the program on Monday. "I think it's probably useful for to us review how the funding has gone, how local law enforcement has used grant dollars to make sure that what they are purchasing is stuff that they actually need. Because there is a big difference between our military and our local law enforcement and we don't want those lines blurred, that would be contrary to our traditions and I think that there will be some bipartisan interest in reexamining some of those programs."

Sen. Carl Levin, D-Michigan, chairman of the Senate Armed Services committee, said his committee would "review this program to determine if equipment provided by the Defense Department is being used as intended."