The FBI reports that overall violence declined nearly 4 percent in 2011, according to an article from USA Today.

This information has been released less than two weeks after a national victims’ survey reported an increase in violent crime last year. However, all categories of major violent offenses declined, although murder showed the slightest decrease at less than 1 percent, the article reports.

The FBI report – the FBI Uniform Crime Report, released Monday – shows robbery and aggravated assault in the largest declines at 4 percent, representing a reversal of the National Victimization Survey, which noted a 22 percent jump in the number of serious and simple assaults, USA Today reports.

The differences arise when looking at the data criteria for each organization’s reporting: The victims’ report is based on a survey of crime victims, and it does not include homicide and arson data. The FBI’s account is a measure of offenses reported to police, and it does not track simple assaults – those that do not involve weapons or serious injury, the article notes.

Because the increase in assaults accounted for the entire jump in the victims’ survey, Carnegie Mellon University criminologist Alfred Blumstein suggested that the assault numbers could be due to deeper probing by survey interviewers, USA Today reports. However, the Justice Department says that there was “no evidence to suggest” that changes in victim interviewing tactics prompted the sudden increase in assaults.