Can a non-rotating black hole start rotating?

Question

Can a non rotating black hole start rotating? Intuitively it is not possible, but intuition often leads to wrong conclusions.
I have only basic physic knowledge, however I like to wonder about relativity, quantum mechanics e.t.c, so even not comprehensive answer would be great for me.

Answer 1

A black hole is characterised by its mass, angular momentum and charge.

If a black hole accretes material that has angular momentum, then that gets added to the angular momentum of the black hole.

Just because there is a singularity at the centre does not mean it cannot possess mass, angular momentum and charge. An electron is point-like and also has all three.

You might object that electron spin is a consequence of relativistic quantum theory, whilst General Relativity is classical. Note though, that the singularity in a rotating (Kerr) black hole is not a point, it is more like a ring, so there is no need to invoke any weird quantum effects to ascribe it an angular momentum.