Three youths have been arrested and appeared in court on Saturday.
Mr Beniston, who works with Whangarei Community Patrol, said Northland elderly frequently opened their door to him without checking - putting themselves at risk.
"So many people out there have got a bit of style about themselves and a bit of blarney and they can talk themselves past some of these [pensioners] and this is how the trouble can start," he said.
He said he had come across elderly widows living alone who were too trusting of strangers. They sometimes left their garage doors open, which meant passersby could not only steal contents, but possibly access the house through an internal door.
Grey Power was working with the Whangarei District Council to get security doors installed at council flats.
Police Community Services manager Inspector Glyn Rowland said the decreasing crime rate meant a reduced risk of attack. However, elderly were more at risk of long-term effects from home invasions.