Daniel J. Conley, an officer with the Pittsburgh Police Department, was shot and killed in the pre-dawn hours of December 30, 1922, in the Hill District. He was killed with a single shot to the upper chest by Henry Jackson.
Conley was walking his patrol when he approached four young men whom he suspected of carrying liquor. He was apparently enforcing an informal 3am curfew. When he questioned the men, Jackson pulled a gun, shot him, and fled.
The police put out a dragnet, in which dozens of black men were arrested and a shoot to kill order was issued. A lengthy investigation followed, which focused on a jacket found near the scene.
Jackson was arrested in June 1923 after robbing a man in the Hill District; he was linked to the Conley murder by descriptions provided of the man who purchased the jacket.
At trial, Jackson was convicted of first-degree murder and sentenced to death. He was executed on March 30, 1925. His was the first execution for killing a police officer in Allegheny County history.