Staten Island District Attorney Dan Donovan likes to recite a big statistic on the campaign trail as he runs for Congress: his felony conviction rate, the highest in the city. But there's more to that number than immediately meets the eye. NY1's Courtney Gross filed the following report.

Back in 2003, Dan Donovan ran to be Staten Island's district attorney, repeating, "Over the last four years, Staten Island has had the worst felony conviction rate in the entire city of New York."

He promised to change it. 

"When I took office, Staten Island ranked fifth out of five DA's offices. My first year in office, we ranked first, and we've been there for the last 12 years," Donovan said.

It's an frequently repeated line at his campaign events and by his supporters. 

"He's transformed the district attorney's office on Staten Island from having the lowest felony conviction rate to the highest felony conviction rate in the city of New York," said Dennis Quirk, president of the New York State Court Officers Association.

Data provided by the state division of criminal justice services shows that Donovan had a 98 percent felony conviction rate in 2013, the last year the state had numbers available. His office did indeed lead the other five boroughs, a turnaround from 2003, when the borough ranked last. 

But of course, the numbers can be a bit nuanced. 

"I would caution anybody against just reading too much into that statistic," said criminal defense attorney Arnold Levine. "There's really a lot that goes into whether somebody's a good prosecutor or not."

For instance, Donovan saw just a fraction of the number of cases his counterparts in the other four boroughs did. Brooklyn had almost 10 times the amount of cases as Staten Island. 

As for how this all plays out, it's most likely not in the courtroom. For one, the vast majority of felony cases are plea deals. In fact, barely any make it to trial. Fourteen did in 2013.

"Staten Island has a notoriously conservative jury pool. The defendants know that," Levine said. "The defendants know that their chances of going to trial and being successful are pretty slim, whereas the defendant in the Bronx knows his chances of going to trial is better."

A spokesman for the district attorney attributed the conviction rate to "best talent available, indicting more cases, raising expectations, and good old-fashioned hard work."