Officers had also been investigating whether a car fire on Saturday in nearby Netherhouses and a fire at a derelict house on Wotherspoon Crescent were linked to the incident.
Det Supt Michelle Findlay, from Police Scotland’s Major Investigations Team, said her thoughts remained with Watson’s family and friends.
She added: “Specialist officers are supporting them as we continue to try to get answers about what happened.
“We’ve been carrying out extensive inquiries, including door-to-door in the area, CCTV review and forensic analysis.”
Police Scotland urged anyone with information about the death to contact officers, external. A dedicated online portal, external has also been set up.
Supt Jocelyn Thomas said: “We understand the local community is concerned by what has happened, however we believe this was a targeted attack.
“I want to reassure everyone, these incidents are rare.
“An increased police presence will remain in the area as we continue our inquiries and anyone with concerns can speak to these officers.”