Genealogical Research for St. Peter's Cemetery
Try these sites:

We have incomplete records at the cemetery because of a fire in the caretaker's house decades ago which burned cemetery records.

Find a grave --this might be the most helpful site

Maryland Genealogical Society

Maryland State Archives
Reference & Research :

Guide to Catholic Church Records: St. Peter the Apostle: IRISH - This parish was established in 1842 at Hollins and Poppleton avenues to serve the Irish Population of the Western section of Baltimore City. After World War One, it would also serve the LITHUANIAN population on the West Side of the City. There are no internment records available, although some may be found as part of the records for St. Peter's Cemetery.
Microfilm Number M1434-M1439
Questions regarding Archives collections and services should be directed to the Reference Services Department at: ref@mdsa.net

[PDF] Archives of the Archdiocese of Baltimore Parish Microfilm Collection