One or two words can be enough to turn a hostage situation, so language and rapport is everything, a former New Zealand hostage negotiator says.
"The first thing is to establish communication. The second thing is to establish a rapport with the person or persons and then just to try and calm the situation down and keep it all very controlled," said Lance Burdett, former national adviser for the New Zealand police negotiation teams.
"It's about getting the information as to what they want and why."
Mr Burdett, who worked in police hostage negotiation for 13 years and co-ordinated the negotiations for the Napier siege in 2009, said being open-minded and remaining calm was key.