Police have arrested a fourth person in relation to an aggravated robbery that left a Waikato security guard with a head injury.
Officers were called to a Te Awamutu business on 23 March and found a vehicle had been used to gain entry and the guard injured.
Police said two young people were arrested that day and a third two days later.
An 18-year-old man has now also been charged and was due to appear in Hamilton District Court today.