A Philadelphia man who avoided a conviction in city courts despite 44 arrests for armed robbery and other crimes will now serve at least 32 years in federal prison.

John Gassew, 25, was found guilty Wednesday of two counts of robbery and two counts of possessing a firearm while committing a crime. The verdict was returned by a U.S. District Court jury that deliberated over two days.

Federal prosecutors picked up the case in 2010 after The Inquirer profiled Gassew's virtually penalty-free journey through the local courts. For more than a decade, the U.S. Attorney's Office has used its tougher penalties and greater resources to prosecute selected cases ordinarily handled in the city's Common Pleas Court.

Assistant U.S. Attorney Linwood C. Wright Jr. said the convictions would not have been possible without "witnesses who are willing to come forward and victims who are willing to hang in there." He prosecuted the case with Assistant U.S. Attorney Ed Zittlau. Zittlau said four victims identified Gassew as the robber.

In the city court system, case after case collapsed after victims failed to show up to testify.

Gassew was found not guilty of one robbery charge and one gun charge. Nevertheless, a 32-year sentence is guaranteed because he was convicted under a federal gun law that requires a mandatory seven-year sentence on the first count and a mandatory 25-year sentence for each following count. Plus, there is no parole in the federal system. He is to be formally sentenced in May.

Gassew did not react to the verdict. A small group of friends and relatives was in the courtroom.

In one of the two robberies of which Gassew was convicted, he held up a 7-Eleven store on the 8000 block of Oxford Avenue and beat the store clerk with a .45-caliber semiautomatic pistol.

Police spotted Gassew within minutes of the robbery in October 2009, when he smashed a stolen truck into a tree and ran off, police said. They recovered the gun from the truck. He was shot in the arm.

When Gassew was charged in 2010, he was in a wheelchair. His head was scarred, and his right eye seemed blinded - injuries apparently suffered in an altercation with police after his shooting. Wednesday, he still appeared to be blind in one eye.

The Inquirer series found that Gassew was a typical defendant in a system where nearly two-thirds of those charged with violent crimes escaped conviction on all counts. The series said about 20 robbery cases against Gassew were dropped by city courts after witnesses failed to appear in court.

Despite having the highest violent-crime rate among major American cities, The Inquirer found, Philadelphia had the lowest conviction rate for violent crime. The court system and the Philadelphia District Attorney's Office have since instituted a variety of reforms to shorten lengthy delays in taking cases to trial and to streamline other segments of the system.

Selective in the cases they bring, federal prosecutors choose those they were likely to win and notched a 95 percent conviction rate. Tough federal sentencing laws routinely lead to prison terms of 20 years or longer.

Federal prosecutors have used a law called the Hobbs Act to go after robbers who hit gas stations, convenience stores, and other businesses that they can show are involved in interstate commerce.

In the case of Gassew, prosecutors charged him with violating the Hobbs Act and carrying a firearm during a crime of violence.