I wouldn't put it past somebody

I wouldn't put it past (someone)

Based on that person's pattern of behavior, it is not impossible to imagine them engaging in that kind of bad behavior. Do I think Joe stole the money? Honestly, I wouldn't put it past him. He has no conscience. It seems a bit far-fetched that the government is spying on us with our own appliances, but I wouldn't put it past them.
See also: past, put
Farlex Dictionary of Idioms.

I wouldn’t put it ˈpast somebody (to do something)

used to say that you think somebody is quite capable of doing something surprising, unusual, etc: ‘Do you think he’d ever steal from his friends?’ ‘I wouldn’t put it past him.’
See also: past, put, somebody
Farlex Partner Idioms Dictionary
See also:
  • I wouldn't put it past (someone)
  • wouldn't put it past someone
  • hardball
  • code of practice
  • practice
  • sexual misconduct
  • on a slippery slope
  • slippery slope
  • slippery slope, a
  • the slippery slope