Pennsylvania has more that 70 county jails, where those accused of crimes or awaiting transport to state prison or are housed until sentenced. That sheer volume of inmates makes it impractical to obtain a daily copy of arrests, and there is no service providing them, but you can contact individual facilities for inmate information. You'll need to know the name of the person you are attempting to locate, and additional identifying information might be needed.
First Things First
To start, you'll need to obtain the information about the person you are trying to find. At a bare minimum you'll need the inmate's full name and date of birth, and ideally an idea of which facility where he might be held. When a person is arrested, he is assigned a Pennsylvania Prison Number (PPN). If you have the PPN, you can reference it when attempting to retrieve inmate information.
Using the Prison System's Inmate Locator
Access the Philadelphia Prison System's website, phila.gov/prisons, to obtain the arrest information for any inmate housed within the Philadelphia Prison System. From the main page click Inmate Support, and then look at the sidebar on the left for the "Locate an Inmate" button. This loads the system's database search interface, where you can enter the inmate data. You can bookmark this page for direct access, if you expect to need it again.
Browse the Results
Scan the results of the query for inmate information. If there is more than one inmate with the same name, look at the date of birth to verify the person you are looking for. The results should provide you with the PPN assigned to the inmate, name, date of birth and the facility where the person is housed. If you do not receive any results from your search, you may have to contact each facility directly.