at random

He first encountered molecular structures at 10 years old, when he sneaked into the school library, picked a book at random, and was captivated by the images, despite not understanding what they were.

If you were to grab a section of the grounds at random, odds are you would be pulling up a chunk of hot asphalt or stiff-bladed grass.

Some detainees were arrested at random and taken to large detention centres, the group alleged.

This makes me suspect that he didn’t choose the desk’s previous owner at random.

They choose audience members at random and can accurately guess their birthdays, their hotel room numbers and the exact dollar amount they won after a night in Vegas.