“If someone has committed a crime worthy of death and is executed and hung on a tree, 23 the body must not remain hanging from the tree overnight. You must bury the body that same day, for anyone who is hung is cursed in the sight of God. In this way, you will prevent the defilement of the land the Lord your God is giving you as your special possession.

And you can’t help but read this and think of Jesus’ execution on the cross. In fact Paul references this verse in his letter to the Galatians in chapter 3:13

13 But Christ has rescued us from the curse pronounced by the law. When he was hung on the cross, he took upon himself the curse for our wrongdoing. For it is written in the Scriptures, “Cursed is everyone who is hung on a tree.”

The person having been executed is under God’s curse and more exposure to this scene would desecrate the land, not necessarily because of the dead body, but because of the reminder of the sin that was committed and the punishment