09/19/2011 05:20 pm ET | Updated Nov 19, 2011

Violent Crime In U.S. Drops For Fourth Consecutive Year

Violent crime has declined across the country for the fourth consecutive year, new federal statistics indicate.

Murder and non-negligent manslaughter, forcible rape, robbery and aggravated assault dropped six percent in 2010, according to FBI data. Property crime fell nearly 3 percent from 2009 numbers.

Those statistics, however, are questionable, former FBI agent Harold Copus told The Huffington Post. According to Copus, crime rises whenever the economy takes a dip.

"Bad guys do not participate in the down economy," said Copus, now head of Copus Security Consultants in Atlanta. "It is not like there is a board of directors meeting and they say, 'Listen, the economy is off, people are being laid off, we need to drop back on crime a little bit.' That doesn't happen. They just have to go and rob more people to make up for it."

The FBI said that the data, which is still preliminary, comes from more than 18,000 city, county, university, college, state, tribal and federal agencies. It is those agencies, and not the FBI, that skews the data, according to Copus.

"I am not going to say the stats aren't sent in that way, but you have to look behind the stats," he said. "I won't name names, but I know there are departments out there that will bundle their stats. For example, they may have seven or eight break-ins at a mall in a given day. They know they won't solve them, so they will write them all up as one incident instead of eight."

Though such break-ins wouldn't be classified as violent crime, they show one way in which crime statistics can be manipulated.

The reasoning? It is politically motivated, Copus said.

"It comes down to political pressure. Large stats make cities look bad and it impacts tourism and any number of things. So you may have a mayor who says, 'You keep turning in numbers like that, and I am going to lose my job -- but you'll lose yours first.'"

That narrative might sound familiar to fans of the television show "The Wire," where the accuracy of crime statistics in Baltimore were called into question. But the controversy isn't just the stuff of TV fiction.

Last year, the NYPD came under fire after a police captain was reportedly forced to step down for falsifying crime stats in an attempt to make crime rates in his precinct seem lower, according to the New York Post.

In police reports, New York City cops lessened the value of stolen objects to reduce the number of felonies and even tried to convince crime victims to not lodge complaints, retired officers told The New York Times in 2010.

The FBI is standing by its preliminary statistics, which the agency has presented in the 2010 edition of the FBI's annual report "Crime in the United States."

A spokesman for the FBI did not immediately return The Huffington Post's call for comment.

But Copus remains skeptical of the new numbers.

"Take them with a grain of salt," Copus said. "If you really want to gauge crime in your area, watch the news. You'll get a pretty good idea where things stand if you see one story after another about home invasions and other violent crimes."