Department profile · Mercer County
Princeton Police Department
Reported as: Princeton PDMunicipal police
Jurisdiction context
Not a civil service jurisdiction
This department is not among the NJCSC Appendix A jurisdictions, so major discipline here follows a different statutory track (generally N.J.S.A. 40A:14), with appeals that usually go to the Superior Court rather than the Civil Service Commission.
See the context on non-civil-service departments.
Reflects the NJCSC Appendix A roster as of 2026-07-04. Context only, not legal advice.
In brief
The Princeton Police Department is a municipal police agency in Mercer County. It reported 14 sworn officers in 2025 and 18 internal affairs investigations that year. Its rate of 128.6 investigations per 100 officers was above the 125.6 median for municipal departments. One of the 18 investigations detailed for 2025 reported a sustained complaint. Demeanor was the most frequent allegation label, ahead of other criminal violation and loss of or failure to safeguard agency property.
No major discipline records appear in the 2020 through 2025 releases, and the absence of records is not itself a finding. On the report card the department received a B, which the site reports as the 26th percentile of its peer group of 361 agencies in the 1-14 officers band. A higher volume of internal affairs activity can point to more misconduct or to a stronger reporting culture.
Written by this site strictly from the figures on this page; every number is cited below.
Sworn officers, 2025
14[1]
IA investigations, 2025
18[1]
Incidents, 2025
15[1]
Major discipline records
0
All years, 2020-2025
Internal affairs investigations by year
| 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|
| 6 | 9 | 14 | 30 | 18 |
Complaint mix, 2025
Most serious allegation per investigation, as categorized by the reporting agency. Allegations are not findings: of 18 investigations, 1 reported one or more sustained complaints. Officer-level rows list 17 officers involved.[7]
Most serious allegation
| Demeanor | 13 |
|---|---|
| Other Criminal Violation | 2 |
| Loss Of Or Failure To Safeguard Agency Propert | 1 |
| Other Departmental Rule Violation | 1 |
| Conduct Unbecoming/Discredit To The Agency | 1 |
Internal disposition
| Not Sustained | 12 |
|---|---|
| Exonerated | 2 |
| not provided | 2 |
| Sustained | 1 |
| Administratively Closed | 1 |
Against peers, 2025
| Princeton PD | 128.6 |
|---|---|
| County median, municipal police (13) | 133.3 |
| NJ median, municipal police (447) | 125.6 |
Investigations per 100 sworn officers, using the officer counts each agency reported for 2025. A higher number is ambiguous on its own: it can reflect more misconduct, or a stronger internal reporting culture. Medians are computed within the same agency type only.
Major discipline records
No major discipline records appear for this agency in the 2020-2025 releases. Absence of records is not a finding; see the methodology for what this data does and does not cover.
Questions and answers
- How many internal affairs investigations did Princeton Police Department report in 2025?
- Princeton Police Department reported 18 internal affairs investigations in 2025, according to New Jersey Attorney General data. It reported 14 sworn officers that year.
- How many major discipline records does Princeton Police Department have?
- No major discipline records appear for Princeton Police Department in the Attorney General's 2020-2025 releases. Absence of records is not a finding; discipline is listed only after all appeals conclude.
Sources
- [1]New Jersey Internal Affairs Agency Totals, 2021-2025. New Jersey Office of the Attorney General. Sheet "Sheet1", row 2297. Snapshot retrieved 2026-06-09. ↩
- [2]New Jersey Internal Affairs Agency Totals, 2021-2025. New Jersey Office of the Attorney General. Sheet "Sheet1", row 264. Snapshot retrieved 2026-06-09. ↩
- [3]New Jersey Internal Affairs Agency Totals, 2021-2025. New Jersey Office of the Attorney General. Sheet "Sheet1", row 1282. Snapshot retrieved 2026-06-09. ↩
- [4]New Jersey Internal Affairs Agency Totals, 2021-2025. New Jersey Office of the Attorney General. Sheet "Sheet1", row 1785. Snapshot retrieved 2026-06-09. ↩
- [5]New Jersey Internal Affairs Agency Totals, 2021-2025. New Jersey Office of the Attorney General. Sheet "Sheet1", row 767. Snapshot retrieved 2026-06-09. ↩
- [6]New Jersey Internal Affairs Agency Totals, 2021-2025. New Jersey Office of the Attorney General. Sheet "Sheet1", row 2297. Snapshot retrieved 2026-06-09. ↩
- [7]New Jersey Internal Affairs Investigations, 2024-2025. New Jersey Office of the Attorney General. Sheet "Sheet1", row 1. Snapshot retrieved 2026-06-09. Aggregated from every Princeton PD row for 2025; row 1 is the header. ↩