Every crime category tabulated by the state’s Uniform Crime Reporting Division dropped in 2014 for an overall decline of 14.9 percent a year after similar decreases were recorded in all categories except aggravated assault, the Maine Department of Public Safety announced.

But drug arrests actually grew in 2014 as the state dealt with growing heroin addiction and prescription drug abuse, Commissioner John Morris said.

“The past two years of decreasing crime numbers is encouraging, but also tempered with the growing drug abuse issue that all Maine law enforcement faces. As hopeful as the numbers are, drugs are still the driving force for most of the crime in Maine,” Morris said.

Locally, the drop in crime was particularly evident in Lewiston where the overall crime rate dropped by more than 24 percent. The city saw a decrease in crimes like arson and sexual assaults, although there were two murders in 2014, up from zero the year before.

Lewiston also saw an increase in aggravated assaults, although deputy police Chief Brian O’Malley said part of that might be due to a change in the law where some cases of domestic assault are classified as aggravated assault.

In Auburn, index crimes fell by 17.4 percent over the same period. Deputy police Chief Jason Moen said crime dropped in nearly all categories, with the exception of sexual assault — there was one more reported rape in Auburn in 2014 than the year before.

The Uniform Crime Reporting Division tabulates crime data each year based on reported crimes from local, county and state law enforcement agencies.

The state’s overall crime rate of 21 per 1,000 people is based on 27,987 crimes in 2014, far lower than the national average crime rate of 32 offenses per 1,000, based on data from the previous year, officials said.

The biggest drop in crime last year was for burglaries at 22.4 percent. Other crimes that saw declines included aggravated assault, motor vehicle theft, homicide, domestic violence assault, sexual assault and arson.

In the rural areas patrolled by state police and sheriff’s deputies, crimes dropped in every category except robbery, officials said. In cities and towns, the only crime category to show an increase was sexual assault, with six additional cases reported, officials said.

But drug arrests defied the overall trend, growing from 5,599 arrests in 2013 to 5,801 in 2014, Morris said. The Maine Drug Enforcement Agency continues to see significant abuse of prescription drugs and heroin, as well as an increase in out-of-state drug dealers, Morris said.