Jeremiah 41:1-2

41:1 But in the seventh month Ishmael, the son of Nethaniah and grandson of Elishama who was a member of the royal family and had been one of Zedekiah’s chief officers, came with ten of his men to Gedaliah son of Ahikam at Mizpah. While they were eating a meal together with him there at Mizpah, 41:2 Ishmael son of Nethaniah and the ten men who were with him stood up, pulled out their swords, and killed Gedaliah, the son of Ahikam and grandson of Shaphan. Thus Ishmael killed the man that the king of Babylon had appointed to govern the country.

Jeremiah 41:16

41:16 Johanan son of Kareah and all the army officers who were with him led off all the people who had been left alive at Mizpah. They had rescued them from Ishmael son of Nethaniah after he killed Gedaliah son of Ahikam. They led off the men, women, children, soldiers, and court officials whom they had brought away from Gibeon.

Jeremiah 41:18

41:18 They were afraid of what the Babylonians might do because Ishmael son of Nethaniah had killed Gedaliah son of Ahikam, whom the king of Babylon had appointed to govern the country.