Federal Bureau of Investigation or FBI released Monday preliminary information demonstrating a decrease in the number of violent crimes in the United States. The data covers the first six months of 2011.

Compared to the crime rates from the first six months of 2010, violent crimes dropped 6.4% while property crimes were down by 3.7%. This data is based on reports submitted to FBI by 12,500 law enforcement agencies.

The FBI announced a decrease in robbery, forcible rape, aggravated assault, and murder in the first half of 2011. These four comprise violent crime categories.

Reports show the number of robbery declined by 7.7%; forcible rapes 5.1%; aggravated assault 5.9%; and murders 5.7%.

Attorney General Eric Holder reminds the community that despite the steady decrease in the nationwide violent crime rates, people must be vigilant and more work is imperative. He also merited federal agents, the state and local authorities for the improved community participation.

He mentioned the work given to hunt violent offenders involved in organized crime networks, gang activity and drug trafficking.

Holder reiterated that there is an alarming spike in law enforcement fatalities and law enforcement deaths within line-of-duty. He pronounced this as appalling and unacceptable.

FBI cited that the cities having populations between 50,000 and 99,000 showed 7.2%, being the largest decline in violent crimes.

Violent crimes declined across the country, the following data show the rates broken in regions: The Midwest shows the largest decrease in violent crimes at 9.7%, coming next is the West at 6.6%, followed by the South at 5.8%, and Northeast at 3.6%.

Property crime however, demonstrated less decrease in the motor vehicle theft- 5%, larceny -4%, and burglary - 2.2%.

On a separate data gathered, arson cases in the first six months of 2011 in each region in the country dropped by 8.6%.