Wu said he'd never ask staff to put themselves at risk and fight back, but sometimes there's nowhere to run.
In Napier a father and son produced a hockey stick and table leg from behind the counter and fought back after two masked robbers, armed with a claw hammer and crowbar, attacked their dairy on August 26.
Watch the footage here
Sensible Sentencing Trust spokesman Garth McVicar said he was not surprised the staff were armed and warned more would follow suit.
"In a recent attempted burglary in Napier the shopkeepers fought back and chased the wannabe thieves away, the second time that had happened in the same premises in recent times.
"SST is saying either the Government steps up and gives the police the resources and tools to deal with crime and directs the Courts to dish out appropriate sentences or face a backlash from a frustrated and angry public."
He said present legislation wasn't protecting law-abiding members of the community.
"SST believes public safety must be the paramount purpose of all legislation and if the
Government does not have the courage to do what needs to be done SST will encourage victims to fight back," he said.
Police have urged people to call for help instead of taking matters into their own hands.
"Naturally we do not support suggestions that the public should take the law into their own hands," a spokesman said.
"We strongly urge anyone who believes they are facing an immediate threat to their safety, or sees a threat to the safety of others, to call 111 and let police deal with it."
The spokesman said police were "very focused" on working with justice sector partners to prevent crime and reduce victimisation.
Earlier this week Prime Minister John Key echoed the police message, writing an open letter to the Chinese community about burglaries, partly prompted by concerns people would start arming themselves to defend themselves and their property.
The letter, sent to four Chinese newspapers, was aimed at reassuring those communities the Government was taking the issue of crime seriously.
"There has been a little bit of discussion amongst some in the community about people sort of taking the law into their own hands and basically arming themselves and I think we're trying to give them reassurance that's not a good thing to do," he said.
"They should leave that in the hands of the police."
Official statistics for the year ending July 2016 were released yesterday and showed 11,171 more people were victims of offending than the year before. The increase equates to a 2.3 per cent rise in crime.
Police Minister Judith Collins said more than three quarters of the increase could be attributed to burglaries.