Harry (Joe Pesci)’s Timeline and Summary

Harry impersonates a police officer so he can stop by the McCallister house and learn how to undermine their security system.
He comes back with Marv and tries to break in, but Kevin turns on a light, revealing that someone's home. They scurry off.
Later, they almost hit Kevin with their van. After Kevin recognizes Harry from his gold tooth, they trail him in the van, but Kevin evades them by hiding in a nativity display.
Harry and Marv try to rob the house again, but Kevin holds a fake party, using a mannequin and a cardboard cutout and a few other tricks. They back off.
They sneak up to the house a third time—but Kevin scares Marv off with his gangster video.
Yet, Harry realizes that Kevin is home alone, evading them. But Kevin overhears them plotting to return that night.
When they arrive, Kevin is ready. Harry gets shot with a BB gun, burned, coated with chicken feathers, and injured in other ways.
He catches Kevin, by Marley creeps up and beans him with a snow-shovel. Harry gets arrested, and glares at Kevin from the back of a police car.