A government report released yesterday revealed that for the first time, the majority of people being sentenced to federal prison for felony offenses are Latino.

According to the report from the U.S. Sentencing Commission, Latinos made up more than half of those sent to federal prison in the first nine months of federal fiscal year 2011, which began last Oct. 1. And behind the upswing is a rise in felony prosecutions related to immigration.

Immigration-related crimes for which people are prosecuted can range from a serious offense like human smuggling to something as simple as being caught re-entering the country after a deportation.

What is feeding this pipeline? One major driver of immigration-related federal prosecutions has been a post-9/11 border security program known as Operation Streamline. Implemented in 2005, it mandates federal criminal charges for people caught crossing illegally in several border jurisdictions in Arizona, New Mexico and Texas.

Migrants caught crossing illegally in these areas are whisked through the federal court system, quickly convicted and sentenced. From an NPR series on Operation Streamline last year:

They are often arraigned and counseled, plead and are convicted in a matter of hours.

These illegal immigrants are coming for jobs or to reunite with family — and have no other criminal background. Immigrants in these circumstances used to be returned voluntarily, or they went through the normal administrative deportation process. Now, they leave as convicted federal criminals.

The federal government has praised Operation Streamline as a deterrent to illegal border crossings, which have been down in recent years. But there has been controversy over just how successful these measures are (the economy has also played a role in deterring illegal entries) and how Operation Streamline has affected the federal courts and their workload. And while the sentences are short, typically ranging from one month to no more than six, there is also substantial controversy over how much the program costs.

Either way, immigration-related prosecutions now top the list for federal prosecutions overall, according to the Transactional Records Access Clearinghouse at Syracuse University, which tracks law enforcement and court data. According to a recent TRAC report, illegal entry was the top charge, followed by illegal re-entry.

The Latino prison statistics are prompting discussion about their ties to immigration policy, according to one Associated Press story:

The demographic change in who is being sent to federal prison has already prompted debate among commissioners and experts studying the impact of expedited court hearings along the border.

“Statistics like this have to start drawing attention to this country’s immigration policies and what we’re doing, if this is one of the results,” said Fordham University Law School professor Deborah Denno, an expert on racial disparities in the criminal justice system.

The federal government sentencing report can be downloaded here.