From a distance, it looked like Wyatt Nease was using a handset to operate a remote control car. However, the small wheeled vehicle zipping across the carpet was not a child's toy but the very adult Pointman Tactical Robot.

"Swat teams absolutely love it," said Nease, an unmanned systems specialist with Applied Research Associates. "You can throw it through windows and doors, it goes up stairs, it's self-righting. We can mount 12-gauge shotguns on it, so we can weaponize it as well."

The Pointman is one of the star attractions in the seventh annual Border Security Expo at the Phoenix Convention Center in Arizona. The trade show is a festival of surveillance and combat technology and a chance for the private sector to pitch their wares to federal agencies with multi-billion dollar budgets.

The location is no accident: Arizona is key to the US government's immense efforts to secure the almost 2,000-mile-long frontier with Mexico. According to Department of Homeland Security statistics, 123,285 people were apprehended near Tucson in 2011 as they attempted to cross the border illegally, out of a nationwide total of 340,252. The effort has been given added urgency by Barack Obama's second-term push for comprehensive immigration reform, with the president offering tightened border security to secure Republican support for his proposals.

The Expo began on Tuesday and concludes today. About 185 companies are showcasing everything from gates to guns, drones to portable toilets. A stall offering self-heating meals was next to a table of firearms.

Costing between $23,000 and $35,000, Nease said the Pointman was initially available only to the military. Now it is used by the likes of the FBI and LAPD for reconnaissance before humans enter potentially threatening environments. Nease said that the guns are used to shoot doors, not people.

"You can send this robot up to a door, blast it and go right on through," he said. "You can add teargas canisters to it. If someone tries to come up to it you can detonate the teargas canister and haul ass out of there." Other optional extras include strobe lights and shrieking noises to disorient suspects.

Also on display was the company's Nighthawk, a drone the size of a small model airplane that comes ready to launch in a portable tube and is operated using equipment that can be carried in a backpack. Nighthawk is designed for surveillance and reconnaissance missions but Nease said it was theoretically possible to turn it into an assault weapon. "You could take this camera pod here," he said, opening a hatch, "pack it full of C4 [plastic explosive]: flying bomb."

To the rescue? A remote-controlled drone. Photograph: John Moore/Getty Images

The Qube is a bijou drone designed for first responders in situations such as manhunts, stand-offs and fires. Less than 1m wide and weighing only 2.5kg, it costs from about $50,000. It has zoom, infrared and thermal capabilities and can fly for up to 40 minutes at an operational altitude of 100-500 ft.

"The FAA is just beginning to open the airspace for these public agencies, so we're really at the very start of them being able to use a tool like this," said Kristen Helsel, from the maker, Aerovironment. "Small unmanned systems are very versatile and that eye in the sky is so powerful."

Many products have the potential to affect the lives of Americans who never go near the border. A company from Florida is pushing license-plate recognition software that could help police making traffic stops but also appeal to ordinary businesses who want to catch people who are parking in the wrong spaces.

Panasonic displayed a wearable video camera system for law enforcement officials that is roughly the size of a badge and gathers sound and images that can be used in court.

Integrity Ballistics promoted their "less-lethal" ammunition. The round splatters into a pancake shape on impact and, says their brochure, should help the shooter "obtain the proper amount of pain to enable target compliance."

The hall was a dense forest of cameras. All-seeing eyes mounted on hydraulic stalks soared towards the ceiling from the backs of flat-bed trucks, like high-tech versions of the "car periscope" trialed by Larry David in Curb Your Enthusiasm.

"This looks like any other farmer's truck," said David Nichol, president of Tucson-based Strongwatch. But in the back was a surveillance camera that can be raised to full height in about 20 seconds. Quick operation from unmarked vehicles allows border patrols to scan without being spotted.

"Transnational criminals have all these moles, they call ahead as [patrols] are deploying," said Nichols. He said that customers ranged from border sheriffs to a state-level anti-terrorist group.

Nearby, a camera with a head like Star Wars' R2-D2 whirled endlessly on a pole through 360 degrees. This was part of a "virtual fence". Position the cameras around the perimeter of a property and they can autonomously detect distant movement, decide whether they are seeing a wild animal or a potential criminal and alert a command center that might be thousands of miles away. The system aims a harmless laser beam at intruders to scare them. "We stress, non-lethal lasers," Nichol said. "The laser beam is intended to chase people away. It can pick them up from 350m."

DRS Technologies has installed systems in Egypt and Jordan and its sensors are used by the US army in Iraq and Afghanistan. Its ground surveillance radar can detect a walking person from about 13km away. DRS is bidding for a contract with the US Customs and Border Protection's Fixed Towers program – a planned series of sensor arrays in Arizona designed to detect incursions.

Local police browsed the booths. Yet even the sharpest equipment would have struggled to find a federal decision-maker with a check-book. Exhibitors are worried that federal budget cuts will harm business. Several senior officials who had been slated to give speeches canceled their appearances and stayed in Washington because of travel cutbacks.

The Border Security Expo is in its seventh year. Photograph: Joshua Lott/Reuters

"I'm curious to see what'll happen with sequestration," said John McKinney, director of Explora Security, which has offices in the US, UK and Jordan and has clients including NATO, the UN and the US military. It displayed a modular, mobile yet explosion-resistant tower that can be built in a couple of hours.

McKinney believes it is more cost-effective than constructing permanent towers and could help border personnel keep drug cartels on their toes.

"When people learn your patterns they find ways to go round that," he said. "As the border heats up, agents need something to protect them. It operates as a command center."

Two themes emerged from a day at the Expo: equipment and technology used by the US military is increasingly becoming available to domestic entities. And software is now easy to use and more powerful. Physical Security Information Management (PSIM) software potentially gives officials huge surveillance powers whether in a desert or a metropolis.

PSIM makes it possible to merge and share vast amounts of information to make incident responses more efficient. It can connect diverse security devices across cities so that everything from elevators, sprinklers and doors in a private office block, to traffic cameras, to barriers, to storefront CCTV, can be controlled from one computer. As in the movies, a person of interest can be tracked through a building and from street to street as the user switches cameras. A photograph of the target and a location map could be sent instantly to police or security guards.

"Threats are always evolving. We've moved from a world where threats used to be single gunmen to a world where threats and risks are much more complicated." said John Gill, a former White House Chief Security Officer who now works for VidSys, a PSIM provider. And the implications for civil liberties? "Issues of privacy are very much up to the customer," he said.