For example, there was a convoy of both Mongrel Mob and Black Power at a funeral held recently for one of homicide victims, he said.
Police have confirmed the three Waikato homicides had all been the targets of gangs.
Huntly man Wayne Noda was found beaten to death in his home on June 30.
Then on July 8, Robert Nelson was gunned down in the Melville home of his partner Kahlee Marfell, who was also shot in the leg.
Marfell lived at Matthews Crescent with her senior Mongrel Mob gang member father, Mark "Griff" Griffiths.
Nelson had been trying to shield Marfell from the bullets when he died.
A 17-year-old who was also in the house was shot four times, after three gunmen knocked at the front door asking if "Mark" was home.
The body of Mitchell Curtis Rehua Paterson, 26, was found in the water below the McLaren Falls bridge on July 13.
Police confirmed he had been beaten to death.
Casson said there had been concern in the region about public safety because the three homicides had happened in such a short spate of time.
"It is true that it is not the general public that are being targetted here but the unfortunate thing is that good people can get caught up in a bad situation if that are just in the wrong place at the wrong time.
"That's what my concern is and that is the concern of a lot of people."
Even in his time as a police officer he had not seen so many homicides in such a short space of time, he said.
"People have to remember, even those these guys that have been killed may have gang links, they are still somebody's son, brother, father."
Casson said police would get to the bottom of it in the end.
"They don't give up because the people involved had gang links, they will be putting all efforts into clearing this up."
