One of the best data-driven stories I have read is "Death in Custody" by Malaysiakini from Malaysia.
Using Tabula, Google Sheets, OpenRefine and some good old-fashioned Javascripting and HTML markup, the reporters were able to analyze 15 years of police-custody deaths and found that most go unreported (about one in four are even known)
Worth a look: https://pages.malaysiakini.com/deathincustody/interactive/