[go] over the wall

to manage to escape from a prison

The idiom "go over the wall" probably comes from the idea of escaping by climbing over a wall. It has been used in different situations, like when people escape from prisons or when soldiers climb over walls during battles. It can refer to physically climbing over a wall to get away, like escaping from a prison.

The inmate is currently attempting to go over the wall as a desperate bid for freedom.
The guards are vigilant, making it difficult for prisoners to go over the wall.
Last month, two inmates successfully went over the wall and eluded capture for several days.
If they don't strengthen security measures, more prisoners may attempt to go over the wall in the future.
Should they find a weakness in the prison's perimeter, they could plan to go over the wall.