Ishmael kills pilgrims
After he assassinated Gedaliah, Ishmael killed pilgrims, threw their bodies into a cistern, and took captives from Mizpah.
Key passages
Je 41:4–10

And then on the second day of the killing of Gedaliah—and no one knew— then men came from Shechem, from Shiloh, and from Samaria, eighty men with shaven beards and torn garments, who had cut themselves with blades, having grain offerings and frankincense …