Darren Morton, managing director of Executive Security Group who served in NZ Police's anti-terrorism and VIP protection units in the 1990s and 2000s, said he would expect Clinton to treated as a "high-risk" VIP when it came to the security around her visit. It was likely she would have some of her own security, bolstered by the police.
"She is a high-profile individual, she would be classed as high-risk, even in a country like New Zealand.
"She is part of the American political scene and that's quite a topical scene at the moment.
"The President who is in there at the moment is a very emotive individual who has the ability to rally his base, so to speak, and all it takes is for one person who believes what he's hearing overseas to take it into his own hand and think he's going to sort the problem out.
"The greatest threat is not from an international assassination team or terrorism, it is from the lone, mentally disaffected individual, to be honest."
He said security around US Presidents tightened after the assassination of former President John F Kennedy and the attempt on Ronald Reagan. After that, it became common practice for Presidents to travel in closed cars and get out of the car under cover rather than in the open.
Morton had worked in protection for former PM Helen Clark and Jenny Shipley, including during the Asia-Pacific Economic Co-operation summit in New Zealand in 1999 which President Bill Clinton attended.
It is not Hillary Clinton's first visit to New Zealand, but the security is likely to be less intense than when she visited as Secretary of State in 2010. Then the security around her included special forces on the roof around Parliament and explosives sniffer dogs checking every room at Parliament.
When she travelled to the Cook Islands in 2012 for the Pacific Islands Forum, Rarotonga was treated to an advance plane carrying everything from bulletproof vehicles for her motorcade to security detail.
