Busan police provide personal protection for eight airline workers amid manhunt
The Busan Metropolitan Police Agency said on the 17th that it has begun personal security protection for eight employees of an unnamed airline, including a captain, amid concerns about possible further crimes by the suspect who remains at large.
The protection plan involves the police accompanying the targeted employees in person, the agency said. In this case, authorities chose direct physical protection rather than relying on welfare devices like smartwatches, due to what they described as a heightened risk.
In Busan’s Busanjin District, a man in his 50s, A, stabbed and killed his former coworker B with a knife at about 5:30 a.m. in an apartment, then fled. A had previously worked as a captain for the same airline.
![Comparison of predicted and actual noise attenuation of EP100 elastomeric earplugs (Willson Safety Products). OX axis: the difference between the C- and A-weighted sound pressure level, Lc-La. The larger this value the larger is the low frequency content of the noises. Passive SPEs attenuate low-frequency noise worse than mid- and high-frequency noise.
Top: Results when laboratory data were used (mean attenuation values and standard deviations SD). Markers - calculations for "NIOSH 100 noises"; graphs - noise reduction ratings, NRR (USA), SNR & HML (European Union and RF). The prediction with HML most closely matches the attenuation of various noises.
At the bottom. NIOSH conducted measurements of noise attenuation in factories [1]. They determined the average noise attenuation and standard deviations. The bottom markers and graphs correspond exactly to the top ones, but they are not derived from laboratory data (mean attenuations minus standard deviations). They are derived from the average noise attenuation (without subtracting standard deviations) of earplugs when used by workers in factories. A similar comparison is published in the table in Appendix C in [2].
Calculation methods and initial data:
SNR, HML - ГОСТ ISO 4869-2-2022; ISO 4869-2:2018.
NRR - Environmental Protection Agency (1979). 40 CFR Part 211 — Product Noise Labeling. Subpart B — Hearing Protective Devices. 44 Federal Register 56139-47.
"100 NIOSH noises" - William J. Murphy, Trevor W. Jerome, Hilary L. Gallagher*, Melissa A. Theis* and Richard L. McKinley. Comparison of Three Noise Reduction Rating Calculators for Passive an Active Hearing Protection Devices. EPHB Report No. 360-13a, July 2015 https://www.cdc.gov/niosh/surveyreports/allreports.html
1. Edwards, R. G., Hauser, W. P., Moiseev, N. A., Broderson, A. B., and Green, W. W. (1978). Effectiveness of Earplugs as Worn in the Workplace. Sound and Vibration 12(1), 12-22.
2. Appendix C. Real World Data (page 33). In: John R. Franks, Christa L. Themann & Cari Sheris. The NIOSH Compendium of Hearing Protective Devices (1994). DHHS (NIOSH) Publication No. 94-130, https://ntrl.ntis.gov/NTRL/dashboard/searchResults/titleDetail/PB95243200.xhtml](https://journalkor.site/content/images/2026/03/01_HML_SNR_NRR_hearing_protection_attenuation.jpg)
Earlier, at around 4:30 a.m. on the 16th in Goyang City, Gyeonggi Province, A allegedly throttled another former coworker, C, at the front of an apartment elevator with a tool; C resisted and the suspect escaped. C then reported the crime to police.
Police are continuing to pursue A. They say he left the airline in 2024 after serving as a co-pilot and did not use his vehicle, credit cards, or mobile phone during the incidents, opting to stay hidden.
The airline said it had compiled a list of employees who requested protection and handed it to the police, but could not confirm whether the incidents relate to the company’s operations or the motive.
Police said they identified the suspect through comparisons of physical appearance and other leads, and that all possibilities remain on the table as the investigation proceeds.
Why this matters beyond Korea: The case underscores risks to aviation workers and the potential for workplace violence within the global airline industry. For U.S. readers, it highlights the importance of robust security and crisis-response protocols for airline staff, as American carriers partner with Korean airlines, share supply chains, and coordinate operations worldwide. The incident also points to challenges in tracking individuals who avoid traditional traces, a concern for international law enforcement and cross-border security cooperation.