Laying hands on the ruins actually happened very soon after the city fell (Joshua 6:1–27). In Joshua 7:1–26 Achan took some of the devoted things of the city, and was severely punished just for that: he and his family were burned and stoned to death. For you do not touch what the Lord has forbidden.
34 In his days Hiel of Bethel built Jericho. He laid its foundation at the cost of Abiram his firstborn, and set up its gates at the cost of his youngest son Segub, according to the word of the LORD, which he spoke by Joshua the son of Nun.