First, we must determine which numbers would best gauge prosecutorial priorities. The number of convictions in a given year is affected by juries. The length of prison sentences are influenced by judges. However, who is being prosecuted and for what type of crime is solely within the prosecutor’s discretion (except for the necessity of a grand jury indictment, which is pro forma the vast majority of the time). Our friends at TRAC Reports monitor these numbers nationwide. Below are the number of federal prosecutions brought in each fiscal year from 2000 to 2006 (with 1998 thrown in to provide an earlier Clinton administration benchmark):

Here are the highlights:

1. Prosecutions increased 29 percent between 1998 and 2006 (and, for what it's worth, they're up 59 percent since 1994).

2. Prosecutions peaked in 2004 and have slid a bit during the past two years.

3. Ninety percent of the increase from 1998 to 2006 was due to additional immigration prosecutions.

4. White collar prosecutions have decreased 23% since 1998, and 25% after peaking in 2002.

5. Weapons prosecutions have increased 248% since 1998.

At this stage, LexMetrics is hesitant to read too much into the the numbers above. In New York City, 2006 saw far fewer murder prosecutions than 15 years ago. It wasn’t because local prosecutors deprioritized homicides and shifted resources to other crimes. There simply were far fewer murders in 2006 than in 1991 (597 vs. 2,154). The same argument might be made at the federal level for any one of the above categories.

However, this type of explanation can only be carried so far. Murder is a crime with the least prosecutorial discretion. A dead body will always initiate an investigation, and if there's a legitimate suspect, a prosecution. On the other end of the spectrum are crimes like prostitution and gambling - where there's both a choice to go looking for violatiors and whether or not to prosecute.

The above examples apply to local jursdicitions. Federal prosecutors probably have even more discretion in what type of cases they investigate. So, the rise in immigration prosecutions since 1998, and the fall in white collar prosecutions, would seem to be further influenced by policy changes and political considerations. Judicial Reports will revisit these and other questions down the road.

 
For those interested in how the feds are operating locally, here are the numbers for the Southern District of New York. For the record, the current U.S. Attorney, Michael Garcia was appointed in 2005:

Here are the numbers for the Eastern District of New York. The current U.S. Attorney, Roslynn Mauskopf, was appointed in September of 2002:

Note: The source for the New York City homicide data was the NYPD.