"This was at 7pm this evening with families, young people, children in the mall enjoying a meal in the food court or some shopping," he said.
"I came straight down here to pick that person up."
He praised police but said Kiwis shouldn't have to contend with that kind of lawlessness.
"The members of the public should be able to come out to a mall or a meal without the fear of having to watch the type of violence that's been perpetrated again at the Albany mall tonight," he said.
"This is a continuation of the violent offending we are seeing, especially in Auckland, the Waikato and Bay of Plenty."
Mitchell laid the blame for the recent crimes on the "soft" policies of the Government.
He accused them of only taking some sort of "action in the last six months because they've come under sustained political, media and public pressure".
Police, meanwhile, have encouraged those who witnessed the incident, or have video footage, to contact them via the 105 phone service or online, using Update My Report quoting this number: P052088466.
Information can also be provided anonymously via Crime Stoppers on 0800 555 111 or at www.crimestoppers-nz.org.
Earlier this week, police arrested 14 young people after a spate of commercial aggravated robberies in Auckland and Waikato.
Auckland City police arrested six people after an aggravated robbery at St Lukes Mall last week.
Offenders wearing masks and carrying batons targeted Stewart Dawson's, smashing glass cabinets and grabbing jewellery before fleeing.
About $371,000 worth of jewellery was reportedly stolen from the store.