The images are grainy and police have not determined whether the cyclist is male or female, but said the pictures were taken about the same time Ms Aim would have been walking through or past the school.
She was found lying in a pool of blood by police going to investigate reports of vandalism at the college at 2.30am on January 17.
Detectives yesterday questioned people at a house a few streets from where Ms Aim, 26, was found.
Mr Turner said the street had been part of an initial area canvas after Ms Aim was killed and the officers were catching up with people who had not been home at the time.
Her body arrived back in the Orkneys on Sunday after a 19,000km journey and flags flew at half mast yesterday for her funeral.
Inside the Islands' council offices, the transportation and infrastructure committee stood while the chaplain said a prayer, followed by a minute's silence.
Around 300 people gathered at East Mainland Parish Church in the Orkneys for the celebration of her life.
During the 50-minute service, the Reverend Miriam Gross told mourners: "Let us remember Karen, her beautiful and cheerful personality, her beautiful smile.
"This lovely lady who put a ray of sunshine into every room she came into."
A slideshow featuring Ms Aim was shown in the church, with pictures of her as a young child, with her family, at school, on her graduation day and with New Zealand friends.
Some mourners wept as the lyrics of one of the songs - No One But You (Only The Good Die Young) - were played.
Prayers were said for her, her family and whoever was responsible for her death.
"We pray for the person or persons who fatally injured Karen," Ms Gross said.
The congregation was told she had fallen in love with New Zealand and Taupo, where a memorial was to be erected to her.
Her father Brian Aim said: "I've been put into the most unreal world you could ever imagine.
"The funeral service will surely be the time I will be emotionally struck that Karen's no longer with us."
