Roll of Honor
Incident
Officer William Hennessy and his partner were assigned to check on the conduct of patrons in a nightclub. When they arrived, an altercation ensued in which Officer Hennessy's partner was attacked by an offender. When Officer Hennessy rushed to his partner's aid, the offender began to fire a gun. Both Officer Hennessy and his partner, Officer James Mulcahy were fatally wounded. Two men were arrested and held by the coroner. Both men were indicted in August, 1920; On October 20, 1921, both were acquitted. One of the suspects died in a horse riding accident in 1923 and the other suspect died in 1939.
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- Added to badge.nw
- April 2, 2026
- Last updated
- July 23, 2026
Honored here by 1 sentinel - 1 tribute.
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Tributes
I never knew you. I am standing here anyway.
Patrolman Hennessy served with the Chicago Police Department.
Thank you for your service to the Chicago community. Gone but never to be forgotten.
Rest easy, Patrolman Hennessy.
— S. Vincent Anthony, U.S. Army 1985-1993
Agency
Service Record
Incident Details
Patrolman William E. Hennessy is one of 17,623 officers killed feloniously — deliberately targeted and murdered in the line of duty across the full record of this memorial — 54.2% of all 32,508 officers honored here.
In IL, 842 of 1,318 officers were killed feloniously — deliberately targeted and murdered in the line of duty — 63.9% of this state's fallen. That is 9.7 percentage points above the national rate of 54.2%.
At Chicago Police Department, 396 of 571 officers on record were killed feloniously — deliberately targeted and murdered in the line of duty — 69.4% of this agency's fallen.
National Cause Distribution
How Felonious compares to all causes of officer death in the memorial record. William E. Hennessy's cause is highlighted.
How William E. Hennessy Compares
Offender Outcome
Acquitted
When Felonious Deaths Occur
Monthly distribution of Felonious deaths across the full memorial record. William E. Hennessy is highlighted in Aug.
Weapons Used Against Officers
Most common weapons in felonious officer deaths. William E. Hennessy was killed by gun; unknown type.
Others Who Wore This Badge
570 officers from Chicago Police Department are honored on badge.nw. Showing the 16 most recent.
