Assaults recorded in Napier have spiked in recent months, while the number of assaults in Hastings remains unchanged.
Despite a growing population and a rising number of burglaries, assaults in Hastings haven't increased in several years, according to police data.
The figures were part of data analysed as part of the in-depth look at crime data led by Herald Insights.
It may be a certain police operation has taken place and the outcome in reality is a decrease in crime.
The number of assaults in Napier had not changed significantly from July 2014 to near the end of last year, but spiked in January.
Sociologist Jarrod Gilbert cautioned against interpreting spikes in data as evidence that more crime was occurring.
"The problem with looking at data in isolation is it doesn't take into account discrete variables.
"It may be a certain police operation has taken place and the outcome in reality is a decrease in crime."
There were close to 1300 assaults recorded in the Hastings district in the two and a half years to December 2016, and 865 in Napier.
There were an additional 176 assaults recorded in Napier from January to April this year - 50 of these were in January alone.
The most common days for assaults, unsurprisingly, are Friday, Saturday and Sunday.
In Napier, common assault is recorded as frequently on a Friday as on a Sunday, but in Hastings far more assaults take place on a Friday.
A police spokeswoman said she believed the spike was part of "normal fluctuations", and was not significant.
There were 50 assaults recorded in Napier in January, compared with 34 in January 2016.
In 2015, 312 assaults took place in Napier, 397 in 2016 and 176 in the first four months of this year.
Assaults of all kinds happened more frequently in the afternoons than at any other time.
Burglaries and thefts from retail premises rose significantly over this time, as did illegal use of a motor vehicle.
Former Eastern District Commander Sandra Venables said there were fewer non-violent crimes in recent months.
"It has been improving since it peaked in November."
For more data on crime in your area, go to Herald Insights - Counting Crime.