Police are investigating whether the bombs were thrown by members of the Janitors' Union retaliating against Jesse Binga, colored real estate dealer who had been hiring non-union janitors, or whether intended as another warning to the colored people to keep out of residential districts that have been hitherto exclusively white.

Post, April 7, 1919:

Bomb Explodes in Flat Where Negro Moved In

Tribune, April 7, 1919:

Bomb Set Off in Negro Flats

White residents of the district had held indignation meetings because he had peopled his building with colored folks.

Herald-Examiner, April 20, 1919:

Office of Wimes & Lassiter, Negro Real Estate Dealers, Was the Target

Tribune, May 18, 1919: