TULSA, Oklahoma - Tulsa Police say there's a link between the cold and crime. 

There weren't any homicides in Tulsa during the extremely cold stretch we just snapped.

Police say that's probably because of wind chills dipping dangerously below zero. 

And other crimes either spike or go down because of cold weather.
"People do not like getting out in very, very cold weather," said Tulsa Police Sergeant Shane Tuell.  

Tuell says that changes the type of calls they run every day in Tulsa. 

"Domestic violence calls for service tend to go up a bit whenever it gets cold because families are staying inside together and tempers seem to flare," he said. 

But Tuell says aggravated assaults drop when the temps do because people aren't hanging out outside like they do when it's warm. 

"It's usually they're in parks, public areas, public venues that drinking goes on," he said.  

We added up the numbers from Tulsa police. 

Officers responded to more than 800 aggravated assault calls last summer compared to about 600 last winter. 

We found the same trend in 2016, with nearly 800 aggravated assault calls during the summer compared to 595 that winter.

"This current stretch of having a really, really cold winter so far has really curbed a lot of the calls we've had as far as aggravated assaults," Tuell said. 

He says gang crime also goes down along with robbery calls.
"If you were to do a scientific study there's no way you could not account weather in that scientific study," Tuell said. 

The exception is auto theft. Police say there's a spike in the winter and the summer. 

"What happens in the hot months is people go out, start their car to let it cool down. And the opposite happens in the cool months. They'll go out and start their car to let it warm up," said Tuell. 

Police say the mild winters we had over recent years also plays a role.

Again, there have been zero murders so far this year. 

There was 81 last year.