There are many laws in Philadelphia, both civil and criminal. Violating civil laws may ultimately cost people money, but violating criminal laws may result in a person losing their freedom while being in jail. These many criminal laws range from traffic regulations to laws prohibiting murder and other violent crimes. As people know, the more violent or dangerous the crime, the more severe the penalty will be.
One incident can even lead to multiple criminal charges as well. Depending on what happened, certain charges will be worse than others. One example of this is that people can commit a number of felonies such as aggravated assaults, rape, burglaries, kidnappings and many others and just be charged with that offense. However, if the person used a gun during the crime, they can also be charged with gun charges, if they are prohibited from possessing a gun.
Being charged with the gun charges alone could result in jail time even if the person would not be sent to jail for the primary offense. However, these cases are very fact specific and there may be defenses available to the person. There are many potential defenses, but many times the defenses start with whether the police properly obtained the evidence in the case. If it was done improperly, then key evidence could be suppressed. This would make a conviction much less likely.
If a person is accused of committing certain crimes, they could be charged with additional gun charges if a gun was involved. That means that the person could be facing jail time for two different crimes stemming from the same incident. However, everyone is innocent until proven guilty and there may be defenses available.
Source: Pennsylvania State Legislature, "Pennsylvania statute Chapter 61 section 6103" accessed on March 21, 2016