I'll stand out and disagree with most here on this one.

Keep copies of abusive phone messages let the police know that you have concerns

from this attention.

Then tell him (recorded) that it's been over for a long time and you wish it to stay that way.

If you're talking to him for the benefit of the recording, it won't be too overwhelming.

Forget mace, buy a 10kg CO2 extinguisher. This is more likely to deter him and frostbite

on his face is a good bit of evidence. It works on fires too.

Good luck dealing with this shit of an ex.

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Calm, quiet, smooth, devastating