The Fifth Circuit has determined that persecution requires sustained, repeated harm. As such, it deferred to the agency’s determination that a petitioner who was threatened on three occasions, and physically harmed on one occasion, did not suffer harm rising to the level of persecution.
The full text of Gjetani v. Barr can be found here:
http://www.ca5.uscourts.gov/opinions/pub/18/18-60827-CV0.pdf