Arahants and suicide I'm aware of a story in the Pali Canon where a monk commited suicide by slitting his throat and achieved arahantship at the moment of death. 

Where in the texts can i find this story?

Thank you for your time.
There might be something along those lines in SN 4.23 Godhika Sutta.

Page 85 of The Patimokkha Rules
Translated &amp; Explained says,


  Case (b) is apparently derived from SN 4.23, where Ven.
  Godhika takes his life and gains arahantship just moments before death