The Norther Ireland article specifically covers a few of the reasons why this works.
Edit: I realized that I didn't respond to your question of whether this demonstrates an improvement in Camden. Citylab seems to think so, but offers a nuanced explanation of why this may not be the case and what other factors are at play [3]
[1] https://www.sipri.org/commentary/topical-backgrounder/2019/p... [2]https://www.centreforpublicimpact.org/case-study/siezing-mom... [3] https://www.citylab.com/equity/2018/01/what-happened-to-crim...