A Philadelphia man who had been arrested 44 times for robberies and other crimes but was never convicted in city courts was sentenced Tuesday in federal court to 37 years in prison for two armed stickups.

The lengthy rap sheet of John Gassew, now 25, was highlighted in a 2009 series published in The Inquirer about how Philadelphia had the highest violent-crime rate among major American cities, but had the lowest conviction rate for those offenses.

The Inquirer reported that about 20 of the robbery cases against Gassew were dropped in city courts after witnesses failed to appear in court — in some instances giving up after repeated delays.

In 2010, the U.S. Attorney's Office charged Gassew with three robberies and carrying a gun while committing a crime of violence.

Earlier this year, a federal jury found Gassew guilty of two of the robberies.

Gassew was found guilty of threatening employees and customers with a gun during a robbery at Danny Boy's Bar at 7447 Torresdale Ave. in December 2007. He also was found guilty of robbing a 7-Eleven at 8101 Oxford Ave. in October 2009, making off with cash and cigarettes after beating the clerk with a .45-caliber semiautomatic pistol.

Police confronted Gassew minutes after the robbery and shot him in the arm when he smashed a stolen truck into a tree and tried to run away. They found the .45-caliber gun in the truck.

Federal prosecutors work with the Philadelphia Police Department to identify criminals who can be charged with offenses that carry far more severe penalties than what the offender might face under Pennsylvania law.

When Gassew was convicted, Assistant U.S. Attorney Linwood C. Wright Jr. praised witnesses who were "willing to come forward and victims who are willing to hang in there."

U.S. District Judge Anita Brody also sentenced Gassew to five years of supervised release and ordered him to pay the victims a total of $7,194 in restitution.

After The Inquirer series, the court system and the Philadelphia District Attorney's Office instituted changes to shorten lengthy delays in bringing cases to trial and to streamline other parts of the system.

Contact Robert Moran at 215-854-5983 or bmoran@phillynews.com, or follow @RobertMoran215 on Twitter.