Regarding the common people who were left behind in Judah, this: Nebuchadnezzar king of Babylon appointed Gedaliah son of Ahikam, the son of Shaphan, as their governor.
When veteran army officers among the people heard that the king of Babylon had appointed Gedaliah, they came to Gedaliah at Mizpah. Among them were Ishmael son of Nethaniah, Johanan son of Kareah, Seraiah son of Tanhumeth the Netophathite, Jaazaniah the son of the Maacathite, and some of their followers.
Gedaliah assured the officers and their men, giving them his word, "Don't be afraid of the Babylonian officials. Go back to your farms and families and respect the king of Babylon. Trust me, everything is going to be all right."
Some time later - it was in the seventh month - Ishmael son of Nethaniah, the son of Elishama (he had royal blood in him), came back with ten men and killed Gedaliah, the traitor Jews, and the Babylonian officials who were stationed at Mizpah - a bloody massacre.
But then, afraid of what the Babylonians would do, they all took off for Egypt, leaders and people, small and great.