This is an independent data project created and maintained by me, Joe Rowland. The data for 1963 through 2016 comes from Northeastern BARI’s Boston Data Portal: https://dataverse.harvard.edu/dataset.xhtml?persistentId=doi:10.7910/DVN/1J0IBN, with missing data filled in using SHR data obtained from the Murder Accountability Project (https://www.murderdata.org/p/search-homicide-records-by-victim-type.html), the Massachusetts Death Index (https://www.familysearch.org/en/search/collection/1949332), and newspaper research.
Email me if you have any questions.