Crime was up in Howard County in most categories during the first quarter of this year, compared with the first quarter of last year, according to crime statistics released yesterday by county police.

In most categories, including burglary and theft, increases were less than 6 percent, but robberies and aggravated assaults increased more than 10 percent from the comparable three-month period last year.

Over the past three years, robberies jumped from 36 cases in the first quarter of 2000 to 48 during the comparable period last year to 53 this year. Those increases followed a significant drop - from 69 in the first quarter of 1999 - in robberies that police attributed to their then-new robbery unit.

Police Chief Wayne Livesay said the robbery trend disturbs him.

About 90 percent of the people arrested for robbery in Howard have a heroin addiction, he said, and many of the perpetrators are from Baltimore.

"We're not just dealing with Howard County folks here," Livesay said.

To more effectively police robberies, he said, Howard shares information once a month with a regional group of robbery investigators.

Howard detectives cleared 16 robberies in the first three months of this year, compared with 12 cases in the first quarter of last year, according to crime statistics.

"Our detectives are closing more and more cases," Livesay said. "But I'd rather prevent them than investigate them. That's where we need to improve."

The county has also seen a slow but steady increase in property crimes over the past three years, according to first-quarter data.

The number of property crimes increased 3.8 percent from the first quarter of 2000 to the first quarter of last year, and 2.8 percent from the first quarter of last year to the first quarter of this year.

Police attributed such increases to normal crime fluctuations and the county's growing population.

"Our population has gone up substantially, and that typically means that crime goes up substantially," said Pfc. Lisa Myers, a police spokeswoman. "But in this county, the crime rate has gone up only slightly, mostly in nonviolent crime."

Violent crimes, as a whole, are on the rise, too - from 111 during the first quarter of last year to 117 during the first quarter of this year - but fewer homicides and rapes occurred in that period this year.

One homicide and six rapes were reported in Howard County through March this year, compared with three homicides and nine rapes in the comparable period last year.

Overall, the chief said, he believes police "have done a very good job" in recent years.

"We're making the best use we can of technology," he said, referring to red-light cameras and mobile data computers as ways to reduce manpower demands and increase officer productivity.

The sharpest change in the first-quarter data released yesterday came in the category of officers assaulted - down from 31 in the first three months of last year to 18 during the comparable period this year.

"The department takes a lot of proactive measures, such as crime prevention, to avoid assaults from occurring," Myers said. "We always strive to train officers to be as effective as possible without getting injured."