MorComm Systems owner-operator Ian Morris said lower prices and changes in people's perception of their security had led to an increase in sales of closed-circuit television (CCTV) systems in Oamaru.
Last Saturday morning, two separate incidents of home invasion were reported to police.
The first was at 3.45am, when two men - one of them wearing a balaclava - were caught snooping around inside a Weston-Ngapara Rd home.
The intruders were recorded by CCTV cameras at the rural Weston property. The footage had been posted to social media and passed on to police.
In the second, at a Holmes Hill property at 5am, two people were held at gunpoint and assaulted by masked men who broke into their home.
Mr Morris said interest in security systems often rose after crime was reported.
"You get something that happens ... and that drives it."
CCTV technology had improved in recent years, and so had the prices, he said.
Mr Morris said more people were taking responsibility for their own security.
"Some of the systems I have installed have caught multiple people."
Detective Sergeant Hannah Booth, of Oamaru, said police were concerned about the two incidents at the weekend.
"People should be able to feel safe in their own homes."
Saturday's violent incident in the Holmes Hill area was "isolated" and residents "should not be afraid", she said.