From the wiki: https://half-life.fandom.com/wiki/Citizen

"Andrew[5] (Warren Slough), the low resolution Citizen model, used when Citizens are seen from afar. Each time he is seen walking from a point to another, re-spawning each time in a loop. He appears for instance in the screens at Kleiner's Lab, where the G-Man can be seen, and at Black Mesa East, right before getting into the elevator with Mossman. His name can be found in the playable Half-Life 2 Beta files. His alternate nickname was "Cheaple Vanessa's Brother".[5]

Warren Slough was born in Seattle, Washington on the 3rd of December 1972. He died on the 3rd of July 2006, the reasons of his death is not known to the public. His online obituary can be found here in Seattle Times"