John "Jack" Jantzen

Suffolk County Police Department — Yaphank, NY

Felonious

End of Watch April 21, 1991

Age 32

Tour of Duty 6 yrs

The Vigil Panel 137 ›

Gender Male

Incident Service The Sacrifice Department 26

Incident

Police Officer Jack Jantzen was shot and killed when walking in on a dispute with a gun in progress while off-duty at 5:15 am Officer Jantzen entered a restaurant at the corner of Middle Country Road and Stony Brook Road where a man was holding his wife and a restaurant employee at gunpoint with a 12-gauge shotgun. When Officer Jantzen attempted to intervene, he was shot and killed. The suspect then shot and killed his wife and the restaurant employee. The suspect fled the scene. Officer Jantzen's brother, also a Suffolk County Police Officer, was the first to arrive on the scene and find his brother. The suspect was later apprehended and charged with murder. He was convicted of three counts of second-degree murder and sentenced to 75 years to life. He will be eligible for parole in 2066. Officer Jantzen had been a member of the Suffolk County Police Department for 6 years.

Survivors

He is survived by his wife, son, mother, and brother.

In Our Keeping

Permanent identifier: BO-US-NY-ABDACD67
Stewardship: Maintained by NeuraWeb Global Inc.
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.
Police Officer Jantzen gave the Suffolk County Police Department 6 years.
Thank you for your service to the Yaphank community. Gone but never to be forgotten.
Rest easy, Police Officer Jantzen.

— S. Vincent Anthony, U.S. Army 1985-1993

Agency

Department Suffolk County Police Department

Location Yaphank, NY

Platform Identity scpd.suffolk.ny.us.gov.nw

Service Record

End of Watch April 21, 1991

Tour of Duty 6 yrs

Age 32

Gender Male

Incident Details

Cause Felonious

Weapon Shotgun; 12 gauge

Offender Sentenced to 75 years to life

Police Officer John "Jack" Jantzen 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 NY, 754 of 2,147 officers were killed feloniously — deliberately targeted and murdered in the line of duty — 35.1% of this state's fallen. That is 19.1 percentage points below the national rate of 54.2%.

At Suffolk County Police Department, 7 of 27 officers on record were killed feloniously — deliberately targeted and murdered in the line of duty — 25.9% of this agency's fallen.

Suffolk County Police Department

of 27 officers

25.9% Felonious

NY — Statewide

754

of 2,147 officers

35.1% Felonious

Nationwide

17,623

of 32,508 officers

54.2% Felonious