Serious crimes in St. Paul dipped to their lowest level in more than 13 years, according to end-of-year crime statistics released Monday by the St. Paul Police Department.

Victims of Part 1 crimes, which include murder, burglary and theft, decreased by 6 percent last year compared with 2012, according to police data. That was more than a 3 percent drop from 2009 and almost a 29 percent drop from 1999.

“I really think the credit of lowering Part 1 crime doesn’t rest with just the police department,” said Police Chief Tom Smith.

Smith said the decrease is due in large part to the department’s closer relationship with citizen groups, block clubs and district councils and the connectivity of social media.

While the city recorded 14 homicides in both 2012 and 2013, the number of serious offenses in 2013 was down in most categories — including aggravated assault, theft, burglary and motor vehicle theft — from the year before. The number of robbery victims, however, rose nearly 9 percent — to 716 in 2013.

Smith attributed some of that jump to an increase in smartphone theft, on the rise since 2010. The chief said there were about 80 more cellphone robberies last year than the year before.

“It is very concerning to me as a chief,” Smith said.

The department is discussing possible strategies to address cellphone thefts, such as possibly using public service announcements to educate residents, he said.

The number of rape victims cited in the report also jumped nearly 30 percent from 2012, but that was mostly because of a change in the definition of rape used in national crime statistics collected by the FBI, said Sgt. Paul Paulos, a St. Paul police spokesman.

St. Paul once reported only male-on-female rapes, but with the new definition the department is also including same-sex incidents and cases where women assault men, Paulos said.

In all, crime against people was up almost 3 percent while property crimes were down 7 percent last year.