For me, it is 'Salem's Lot in 1979. I haven't seen anything else by him, so that would explain why he will always be Mark Petrie to me.

Seems he was in a lot of really good TV movies in the late 70's/early 80's - shows like

Children of Divorce
The Boy Who Drank Too Much
Salem's Lot (1979) (TV) .... Mark Petrie
Young Joe, the Forgotten Kennedy (1977) (TV) .... Joe, Jr. (age 14)
James at 15 (1977)
The Death of Richie

Who? Got a pic?

James At 15

I'd be particularily interested in seeing that biopic about Joe Kennedy Jr. He really was overshadowed.

I used to make up my own show starring Lance Kerwin and me.
It was titled Normal Curiosity.

James at 15, then Salem's Lot.

James at 15

Lance Kerwin, Youth Pastor
Calvary Chapel of Temecula Valley

"Lance Kerwin serves as the Youth Pastor here at Calvary Chapel. He is a former Hollywood child actor whose list of credits include the NBC television series 'James at 15' and 'James at 16' and the feature film 'Outbreak' starring Dustin Hoffman. Like many actors in the business, the Hollywood lifestyle began to take its toll on Lance. While his life appeared to be on a downward spiral, God was getting ready to begin His work in Lance's life. God gave Lance his first daughter Savannah in 1994. With a daughter in his life now and God knocking on the door of his heart, Lance began to see that there was more to life than fame, drugs and money. Lance gave his life to the Lord and is now sold out for God. He has a hunger to bring the Gospel to the youth of today so that they can know the Savior of his life and avoid the struggles that he went through.

He resides in Temecula with his wife Yvonne and his three daughters Savannah, Trinity, and Terah."

I remember him as James At 15/16, the boy who runs because he wets his bed in The Loneliest Runner, and as the co-pilot who gets killed at the beginning of Enemy Mine.

I'm always surprised when I find out that a kid in a movie or TV show is not really a kid. Lance Kerwin was born in 1960, so he was 19 when "Salem's Lot" came out in 1979! And since he apparently started smoking crack-cocaine in his twenties, it seems it was right on the heels of this.

I, too, remember him mostly from James at 15, though he was good enough in SL.

Really? After 2 1/2 years? Lance Kerwin bump? Really?

looks like a young Axl Rose

He had a likable star presence when i saw him on tv.
He had what Mike J. Fox had.

Didn't he turn to drugs and then became a Pastor?
I remember seeing him inn James at 15/16. Plus Salem's Lot.

I remember him from James at 15. I don't think I've seen him in anything else, but I remember him very well--well, as he looked then.

I didn't know he was in anything other than James at 15/16.

Definitely James at 15. I didn't realize he was in Enemy Mine.