TRENTON Incidents of violence, vandalism, weapons possession, and substance abuse in New Jersey's public schools saw an overall decrease in 2012-13 from the previous school year, according to an annual report released Thursday by state education officials.

In addition, the number of incidents of harassment, intimidation, and bullying reported by districts decreased last school year by nearly 4,300, or 36 percent.

While some of that decline may be due to bullying-prevention programs, state officials said part of the drop is the result of the Department of Education's working with local districts over the last two years to get a better understanding of the criteria for reporting bullying.

"We are pleased to see positive trends this year," state Education Commissioner Chris Cerf said. "Safe and secure learning environments are a crucial part of preparing kids for college and career, and we have invested significant time to provide support and coaching to districts to reduce incidents of bullying and other forms of violence."

The data come from the Violence, Vandalism and Substance Abuse in the School Report, which depends on districts self-reporting incidents.

In the state as a whole, reported school violence saw a one-year drop of 4 percent. Vandalism was down 9 percent; weapons, 7 percent; and substance abuse, 4 percent.

Locally, the picture varied.

The overall violent-incident rate in Camden County went from .83 incidents per 100 students to .79. Gloucester County improved to .67 incidents per 100 from .88 the year before. Burlington County saw an overall increase of .94 incidents per 100 students versus .85 per 100 the year before.

Some South Jersey districts, such as Cherry Hill, reflected the state's overall incident decline.

Cherry Hill's total reported incidents in all categories combined dropped from 235 in 2011-12 to 99 in the last school year. During the period, reported violent incidents fell from 41 to 35, substance abuse went from 26 incidents to 17, and reported bullying dropped from 144 to 23.

Michael Nuzzo, district security director, attributed the big change in the bullying number in part to training of bullying specialists by the district and the state, as well parents and students realizing bullying is being taken seriously by the district.

In addition, he said that in 2011-12, the first year the state's anti-bullying law took effect, many districts were struggling to make sure they did not underreport incidents.

In Camden City, on the other hand, every category but weapons offenses went up. Violent incidents, for example, jumped from 138 in 2011-12 to 163, after the district reporting 10 incidents in 2009-10, and 22 in 2010-11. For 2012-13, the district reported 109 harassment, intimidation, and bullying incidents, compared to 35 the year before.

Tony Bland, head of the state Department of Education's Office of School Preparedness and Emergency Planning, has been working with district. He attributed the higher numbers to more correct reporting by district leadership in the last year, which has included interim leaders and state-appointed Superintendent Paymon Rouhanifard.

"Those three people have consistently said, 'We are going to report more accurately,' " Bland said.

With more accurate numbers, he said, the district can better target resources were they are needed.

Other South Jersey districts, including some of the smaller ones, saw their violence rates go up. Beverly City, a Burlington County district with 307 students, saw the largest rate increase: 10.42 violent incidents per 100 students in 2012-13 compared to 2.93 per 100 the year before.

The next highest was Hainesport Township, also in Burlington County, with 695 students. For the last school year, the district reported 3.88 violent incidents per 100 students, as opposed to .87 per 100 the year before.