Laddie's jacket

In The Lost Boys "Laddie" Thompson wears a greyish jacket with a red collar and red cuffs and three vertical rows of closely spaced buttons.

One of the photos here: https://the-lost-boy-laddie.tumblr.com/image/157601361615 shows the jacket well.

So you might assume that Laddie was a drummer boy or something who became a vampire one or two centuries ago. Except that there is a photo of Laddie Thompson as a missing child on a milk carton. Photos of missing children were put on milk cartons from 1984 to about 2000. Milk cartons didn't have images of little Charley Ross, who disappeared from Philadelphia on July 1, 1874, for example.

So Laddie must have disappeared in the last few years before his photo was on the milk carton.

I always assumed that the jacket was the school uniform of a military academy Laddie attended, or maybe the uniform of a marching band at his school, and that Laddie was wearing it when he ran away or was kidnapped. And I thought that I remembered that Laddie was wearing his uniform jacket in the photo on the milk carton.

But people sell replicas of the Laddie Thompson missing person milk carton, like here: https://www.worthpoint.com/worthopedia/lost-boys-replica-laddie-thompson-1775910385

It says:

MISSING
"Laddie" Thompson
b. 60-20-1976 ht.4ft. wt.50lbs
If you have any information
regarding this missing person
please call
Santa Carla County Sheriffs Department
Missing Persons
1804 555-5911

And the photo shows Laddie wearing a jacket with a hood instead of his military style jacket.

So possibly Laddie was given the jacket by the Lost Boys after he ran away or was kidnapped. And if so, how did they acquire it and did they kill anyone to get it?