The incident happend in Room No.105 of the Tonle Sab Guesthouse, No.4-6, Street 104, Village 8, sangkat Wat Phnom, khan Daun Penh.

According to the article the victim was addicted to (legal) drugs (medicines).

On October 4 2016 a waiter, working at the guesthouse, didn’t notice the victim for having breakfast/dinner.
He/she knocked on the victim’s door but there was no response. Afterwards he/she looked through the window and saw the victim dead, lying in a pool of blood.
The room was closed and secured with a door lock (door chain lock or bar latch).
The door was also blocked (barricaded) with a suitcase. (ទ្វារ​ត្រូវ​កល់​វ៉ា​លី​ពី​ខាងក្នុង; កល់= to place in an elevated position, elevate by means of a wedge; to support; to block)
There was a small kitchen knife found near the victim’s left hand. The police noticed 7 lacerations on the left arm.

The police concluded that the victim died of bleeding out.

Read more here: http://www.koonkhmer.com/forum/viewtopic.php?f=5&t=2282&p=7952