Stan appears first in the Pilot. He is a business man and networker who is a close friend of the Walker Family. His truck pulling in said "Morrison Seed & Tack" on the side. Cordell refers to him as Austin's finest string-puller.
Many fans suspect his involvement with Emily's death.
It appears even more suspicious as of February 7th 2021, because a fan pointed out that the character has two names on IMDB. What could it mean? Probably just a typo, but it's fun to think about.
In episode 4 (Don't Fence Me In) we also learn he's the co-chair at the Department of Public Safety Commission and they approve all new Ranger hires (sus?).
Over the course of the season, he's been sticking his nose into everything involved with the Walker family, and has even been running for DA against Liam (though that will likely prove a fruitless effort, because Stan sucks) since episode 10, Encore.
In episode 17 Dig, Carlos Mendoza admits to Cordell that Stan was behind Carlos's involvement in claiming to be Emily's killer. Cali had come to see Carlos the last time he was in the hospital and there was a man there with her; Stan. He put up the money.