The Fifth Circuit has upheld the application of the persecutor bar to an Eritrean applicant who guarded prisoners who were detained for being perceived political traitors, knew these prisoners faced long imprisonment or death, and still impeded their escape.
The full text of Gebrgzabher v. Garland can be found here:
https://www.ca5.uscourts.gov/opinions/pub/21/21-60223-CV0.pdf