A teenager was due to catch the bus to her hairdressing job when her life was "brutally" taken away, murder detectives said.
Paige Doherty, 15, disappeared from Clydebank in West Dunbartonshire on Saturday.
The schoolgirl's body was found in an area of trees by the roadside two days later, and police have confirmed they are treating her death as murder.
The last known sighting of Paige was at 8.20am when she stopped at a shop selling rolls, having spent the night at a friend's house nearby.
Police Scotland detectives are attempting to piece together her movements before the discovery of her body more than a mile from the Fleming Avenue shop.
They said she would normally catch the bus from East Barns Street to Glasgow city centre and then travel onto Street Image hairdressers in Kirkintilloch.
Her mother Pamela Munro reported her missing when she failed to turn up at the salon and was not heard from that day.
Detective Superintendent Duncan Sloan, from the major investigations unit, said: "Paige was a young, friendly girl with plenty of friends, and for her life to be taken away so brutally at such a young age is unfathomable to everyone.
"We are at the very early stages of this investigation, however I am appealing to anyone who may have any information whatsoever about her movements from when she was last seen in the early hours of Saturday morning to when her body was recovered at lunchtime on Monday.
"It's crucial that I piece together where Paige went after the sighting at the roll shop and her movements over the course of the weekend and I can only do that by appealing for information from the public."
Paige's body was found in a wooded area at the side of Great Western Road, a busy route connecting Clydebank and Glasgow.
A large area remains cordoned off and forensic officers continued to work at the scene on Tuesday.
Mr Sloan did not reveal the nature of the injuries and said a post-mortem examination was due to take place.
He said he is "open to all motives" over the assault.
The detective said: "From speaking with family and friends, it is apparent that Paige was a well-liked, popular girl with many friends, who was keen to finish school and go on to work.
"She independently secured a work placement at a hairdressing shop and would travel by bus into Glasgow city centre and then travel on another bus from Buchanan Bus Station out to Kirkintilloch. Someone may have seen her in this area at the time.
"I am also particularly interested in hearing from anyone who may have seen anyone acting suspiciously in the area where she was found off Great Western Road on Monday lunchtime.
"This is a particularly busy route with lots of cars and buses passing, walkers and joggers on the pavement. Perhaps someone saw a vehicle in the area or people acting out of character or acting unusually - that could help us in the investigation.
"Any information, however small, may help this investigation."
Laura Mason, chief education officer at West Dunbartonshire Council, said: "Paige was a bright and popular pupil with a good sense of humour.
"We are doing everything we can to support our young people at this sad time."
Posting on Facebook, the teenager's mother wrote: "We are absolutely devastated, as many people who know her will be xxx."