Eddie Paskey

Actor (Lieutenant Leslie) — The Original Series

American actor (1939–2021) who played Lieutenant Leslie, the most frequently seen background officer of the Enterprise, throughout the first two seasons and into the third of The Original Series.

Eddie Paskey was an American actor, born in 1939, who joined Star Trek for the second pilot, Where No Man Has Gone Before, and stayed as a regular background performer and as stand-in for William Shatner during lighting set-ups.
As Mr Leslie he appeared in well over fifty episodes, at the helm, in engineering, as a security guard and in landing parties, and was occasionally given a line; the character was named after one of Shatner's daughters. Leslie is apparently killed by the cloud creature in Obsession, yet is back on duty soon afterwards. Paskey also drove the truck that strikes Edith Keeler in The City on the Edge of Forever.
He left the series during the third season and later ran a family business. He died in 2021.