Case Study Snapshot
| Agency Type | County corrections / community supervision (SE United States) |
| Population Monitored | 175 offenders (mix of post-conviction, pretrial, and sex offender) |
| Legacy System | Two-piece GPS (body-worn tracker + ankle transmitter), capacitive anti-tamper |
| New System | One-piece GPS with optical fiber anti-tamper |
| Alert Volume Reduction | 68% (from ~420 alerts/day to ~135/day) |
| False Tamper Alarms | Reduced from ~18/day to 0/day |
| Staff Hours Reclaimed | 1,200 hours/year (0.6 FTE) |
| Annual Cost Savings | $87,000 (staff time + law enforcement response reduction) |
Background
The county operates a community supervision program monitoring approximately 175 offenders at any given time, including post-conviction probation, pretrial release defendants, and registered sex offenders. The program is staffed by 4 monitoring officers who also carry traditional probation caseloads — monitoring is one of several responsibilities, not their sole function.
The legacy GPS system was a two-piece configuration: a body-worn tracker unit (carried or belt-clipped) paired with an ankle-mounted transmitter. Anti-tamper detection used capacitive sensing (measuring electrical properties of skin contact). The system had been in service for 6 years.
The Problem
Three operational issues drove the technology upgrade decision:
1. Excessive False Tamper Alarms
The capacitive anti-tamper system generated an average of 18 false tamper alerts per day across the 175-offender population. Each tamper alert required:
- Monitoring officer review (5-10 minutes)
- Phone contact with the offender (5-15 minutes)
- In many cases, law enforcement dispatch to physically inspect the device (30-60 minutes of officer time)
False tamper causes included: dry skin, lotion application, sock positioning, sleeping posture, and showering. None represented actual tamper attempts. But the monitoring protocol required full response to every tamper alert because there was no way to distinguish false from genuine without physical inspection.
2. Body-Worn Tracker Loss and Failure
The separate body-worn tracker unit was the system’s Achilles heel. Over a 12-month period:
- 23 tracker units were reported lost or stolen (offenders left them at home, lost them at work, or claimed theft)
- 14 tracker units experienced hardware failure (battery swelling, charging port damage, water intrusion)
- Each lost/failed unit cost $400-600 to replace and left the offender unmonitored for 1-3 days during replacement
3. Staff Burnout
The combination of false alerts and tracker management consumed an estimated 25-30% of monitoring officers’ workdays. With only 4 officers sharing monitoring and traditional probation responsibilities, alert fatigue was directly impacting the quality of both functions. Officers reported prioritizing alert processing over meaningful offender supervision — responding to alarms rather than conducting risk-based field visits.
Solution: Technology Upgrade
Device Selection
The county evaluated three one-piece GPS devices through a 90-day pilot with 25 offenders per device. Selection criteria, ranked by program priority:
- False tamper alarm rate (top priority — the primary pain point)
- Battery life (to reduce low-battery alerts)
- Installation ease (officers install during booking)
- Total cost of ownership
The pilot results confirmed that optical fiber anti-tamper produced zero false tamper alarms over 90 days (2,250 device-days), while the other two devices produced 41 and 67 false tamper events respectively during the same period.
Transition Process
- Week 1-2: Officer training on new devices and monitoring platform (4 hours total)
- Week 3-6: Phased transition — new devices installed on offenders at scheduled check-ins (no mass recall needed)
- Week 7-8: Legacy device collection and return to previous vendor
- Week 9+: Full operation on new system
The transition was completed in 8 weeks with no gaps in offender monitoring.
Results: First Year
Alert Volume
| Alert Category | Legacy System (daily avg) | New System (daily avg) | Change |
|---|---|---|---|
| False tamper | 18 | 0 | -100% |
| Low battery | 95 | 28 | -71% |
| Zone violation | 210 | 85 | -60% |
| Device malfunction | 12 | 3 | -75% |
| Genuine tamper | 2 | 2 | No change |
| Other (motion, lost signal) | 83 | 17 | -80% |
| Total | 420 | 135 | -68% |
Key observations:
- False tamper: 18 → 0. The defining result. Optical fiber anti-tamper eliminated false tamper alarms entirely. The 2 genuine tamper events in Year 1 (offenders who actually cut straps) were detected immediately.
- Low battery: 95 → 28 (-71%). The new device’s 40+ hour battery life means offenders who miss an occasional charge don’t trigger alerts. The legacy device’s ~24 hour battery meant any missed charge immediately generated a low-battery alert.
- Zone violations: 210 → 85 (-60%). Improved GPS accuracy (multi-constellation GNSS) and the new platform’s “pass-through” filtering reduced incidental zone alerts. The same zone configurations produced fewer false triggers.
Staff Time Impact
The 68% alert reduction translated to approximately 1,200 hours of reclaimed staff time per year:
- 285 fewer alerts per day × average 7 minutes per alert × 250 workdays = 1,197 hours/year
- Equivalent to 0.6 full-time positions
- Officers reallocated reclaimed time to risk-based field visits, resulting in a 40% increase in home visits per officer per month
Cost Impact
| Category | Annual Savings |
|---|---|
| Staff time reclaimed (1,200 hours × $35/hour fully loaded) | $42,000 |
| Law enforcement dispatch avoided (18 false dispatches/day eliminated) | $32,000 |
| Lost/replaced tracker units eliminated (37 units/year × $500 avg) | $18,500 |
| Reduced strap replacements (longer-lasting optical straps) | $4,500 |
| Total annual savings | $97,000 |
| Less: Incremental device cost (new vs legacy per-day rate × 175 × 365) | -$10,000 |
| Net annual savings | $87,000 |
Lessons Learned
- Pilot before committing. The 90-day, 25-offender pilot provided concrete data that justified the technology switch. Alert rate data from the pilot matched Year 1 results, confirming pilot validity.
- One-piece eliminates the tracker problem. Moving from two-piece to one-piece GPS eliminated an entire category of operational headaches (lost trackers, tracker failures, tracker charging compliance).
- Anti-tamper technology is the single highest-ROI factor. False tamper alarm elimination drove more savings than any other single factor — both in direct response costs and in staff time reclaimed for meaningful supervision.
- Battery life matters more than agencies realize. Low-battery alerts were the #1 alert category on both systems, but 40+ hour battery life cut this by 71% compared to ~24 hour devices.
For technology specifications, see the CO-EYE ONE GPS ankle monitor with optical fiber anti-tamper. For a comparison of anti-tamper technologies, see our tamper detection technology comparison.