Death Classification: Line of Duty Death

Agency: Chicago Police Department

Served: 15 years, 10 months, 21 days

Unit of Assignment / Detail: 30th District - West North

District of Incident (Present Day): 012 - Near West

Location of Occurrence: 

Cause of Death: Gunfire - Enemy

Age at Time of Death: 41


Date of Birth: 23 Dec 1887

Date of Appointment: 10 Jul 1913

Date of Incident: 012 - Near West

End of Watch: 31 May 1929

Date of Interment: 02 Jun 1929


Interment Details

 Cemetery: All Saints Catholic Cemetery - Des Plaines, Illinois
 Grave Location: Grave 3, Lot N7, Block 7, Section 6
 Interment Disposition: Burial


Memorial Details

Superintendent’s Honored Star Case: Panel # B-12

Gold Star Families Memorial Wall: Panel # 18

Illinois Police Officers Memorial Wall: Panel # 2, Line 25

National Law Enforcement Officers Memorial Wall: Panel # 44-E: 16

Officer Down Memorial Page: Listed



 Military Service: No Military Record Found


Incident & Biographic Details

Sergeant John Leo Conley, Star #4636, aged 41 years, was a 15 year, 10 month, 21 day veteran of the Chicago Police Department, assigned to the 30th District – West North.

On May 31, 1929, at 2:10 p.m., Sergeant Conley and his partners, Patrolmen Herbert Hagberg and Joseph J. Murphy responded to a call of a domestic disturbance at 2431 West Thomas Street. They were given strict orders to quell the disturbance or take the man into custody if he would not calm down. They were to investigate a report that Ferdinand Preuss had shot at his wife in a crazed drunken fit. Pruess was known to the officers as a World War I veteran with expert marksmen skills which were noted on his service record.

As the officers arrived on scene, Sergeant Conley and Officer Hagberg exited the squad car while Officer Murphy kept watch while the two survey the situation. Conley and Hagberg made their way and approached the one and a half story residence. They entered the passageway between the front and rear residences and crept to the rear of the house. Approximately 20 feet into the passageway Sergeant Conley came to the corner of the house cautiously turned left. He located a window at eye level and after making sure he heard no sounds coming from inside, peered through the window shading his eyes in order to see into the darkened room.

Without warning, Preuss fired a blast thru the window with his pump shotgun. Sergeant Conley was struck and his body was propelled backwards his arms being thrown back from the blast. As Conley fell to the ground, Officer Hagberg could see a gaping wound in his chest. Officer Hagberg, being close behind Conley, rushed over to rescue him when another shotgun blast was heard. Sergeant Conley was struck in the face. Moving his hands to his face, he discovered that a portion of his face had been blown off. Frantic, he ran screaming approximately 15 feet before he collapsed to the sidewalk.

Patrolman Murphy, hearing the gunfire rushed to the scene, along with concerned neighbors. As he rounded the corner of the building Pruess opened fire at him and anyone who came near. Officer Murphy was struck by gunfire along with John Chorazak and two other bystanders. Pruess then made good his escape, but not for long.

Pruess fled from the residence three miles to the rail yard of the Chicago and North Western Transportation Company. The next morning he was discovered on the tracks in front of 4245 West Kinzie Street; a train had decapitated his body. It was believed by investigators that Pruess took his own life by jumping into the path of a train.

It was later learned that Ferdinand Preuss had also shot his wife. John Chorazek was also killed and Officer Murphy was seriously injured but later recovered. The two other bystanders were also injured and later recovered as well.

Sergeant Conley was laid to rest on June 2, 1929 in All Saints Catholic Cemetery, 700 North River Road, Des Plaines, Illinois. His grave is located in Grave 3, Lot N7, Block 7, Section 6.

Sergeant John Leo Conley, born December 23, 1887, received his Probationary Appointment to the Chicago Police Department on July 10, 1913 and was issued Star #4636. On June 17, 1927 he was promoted to Sergeant and issued Star #568. He earned 7 Credible Mentions during his career. Upon Sergeant Conley’s death, his Patrolman Star was retired and enshrined in the Superintendent’s Honored Star Case. It is unknown why his Sergeant star number was not retired as was customary.

Sergeant Conley was survived by his wife, Mary Agnes (nee O’Brien) and children, James, age 14 and John Charles, age 13.

Incident recorded under Chicago Police Historical Homicide Database, Case #9705.