Unmanned aircraft, or drones, could have been a boon to law enforcement and first responders in the aftermath of Monday's Boston Marathon bombing that has left at least three dead, according to the president of the Association for Unmanned Vehicle Systems International.

"UAS could be an important tool in the tool kit for first responders in the event of an emergency," says Michael Toscano, president of the industry's largest organization. "Whether it is in response to a natural disaster or a tragedy like we saw in Boston, UAS can be quickly deployed to provide first responders with critical situational awareness in areas too dangerous or difficult for manned aircraft to reach."

Monday's bombing killed three people and injured dozens more. On the police scanner in the aftermath of the attack, first responders discussed grounding a helicopter because it needed to refuel. Multiple drones would theoretically solve that problem.

"Our industry is working to develop technologies to provide first responders with the best tools possible to do their jobs safely as they work to protect our communities," Toscano says.

Drones' quick response time, ability to fly lower than helicopters and cost relative to manned aircraft makes them ideal for use during emergencies, those in the industry say. Their usefulness in disaster scenarios is one of the most consistent arguments that the industry has made in recent months as it seeks to avoid legislation that would limit the use of drones domestically.

In February, Peter Bale, chairman of the board for AUVSI, suggested drones may have been useful during the California manhunt that ended with the death of rogue police officer Christopher Dorner and one California police officer.

"Had a [drone] been able to be used in that environment, who knows what could have happened," Bale said.

In recent months, more than 35 states have considered legislation that would put limits on when law enforcement could use drones. Idaho and Virginia have enacted drone-limiting legislation, but the Idaho law includes an exception for "the purpose of taking photographs of gatherings of the public on public or private land," such as marathons, and the Virginia law allows police use for search and rescue missions.

At least one company has begun marketing mobile drone command vans for police use that could be used at large public events such as the marathon and has been used at the Rose Bowl in past years and during the aftermath of Hurricane Katrina.

The "Mobile Incident Command Platforms," being sold by Information Processing Systems of California, are designed for emergency situations, according to its founder, Clarence Boice. The company has sold early versions of the van to National Guards in at least five states. Boice says the van can be outfitted to launch drones and create on-the-go cellphone and satellite signals in the aftermath of a natural disaster or terrorist attack. Monday's bombing overloaded cell towers in the area.

Privacy groups and lawmakers have said they are worried about the proliferation of drones because police have showed an interest in "persistent surveillance" of American citizens and some departments have considered attaching pepper spray or other nonlethal crowd-control weapons to drones.