Andy Dlinn and the other members of the Squirrel Hill Citizens Patrol spend their nights circling around neighborhood "hot spots," looking for vandals, the occasional drug deal and other signs of brewing trouble.

Tours of duty are often quiet in this neighborhood, Mr. Dlinn said, but knowing where certain crimes happen most keeps the civilian officers alert.

An interactive map posted today lets viewers see what offenses are most reported to police in their neighborhoods might benefit community members like Mr. Dlinn and others who are interested in spotting trends, knowing which offenses are reported most, and seeing how one neighborhood compares with another.

Dragging the mouse over a community and clicking on it reveals recently released Pittsburgh police bureau statistics on offenses large and small. The map lists everything from homicides, rapes and burglaries to incidents of vandalism and public intoxication.

This is the second year that post-gazette.com has compiled the information in an interactive map. The new version allows viewers to see 2010 statistics alongside those from the year before. The map also accompanies a post-gazette.com Google map of Allegheny County that displays the location of every homicide reported since 2008, along with the victim's age, race and cause of death.

The statistics reflect crimes reported to city police in 2010. Higher numbers might mean more crime, or simply that residents in some neighborhoods are more proactive in reporting problems. They are broken down as specifically as possible by neighborhood. Squirrel Hill, for example, where the citizen patrol targets four main zones, is separated into north and south sections on the map.

The numbers can raise awareness, but police officials caution that they don't always provide a complete portrait of what is going on in an area. They don't, for example, take into consideration economics, demographics, population and span of an area, which are factors that may contribute to certain crimes. Nor do they show crime trends over an extended period of time.

Talking to residents of a neighborhood or to community members is a better way to measure its overall health, said Ernie Hogan, executive director of the Pittsburgh Community Reinvestment Group. He warned users of the map not to rely exclusively on the numbers in forming an impression of an area.

"Data to you can mean one thing, and data to me can mean another," Mr. Hogan said. "I'd hate for people to judge a neighborhood based on only one tool."

Still, Mr. Dlinn said, it gives a glimpse into what problems exist in a neighborhood and what's going on in the one next door.