Two sisters, whose identities along with the victims are protected under Canada's Youth Criminal Justice Act (YCJA) as they were minors at the time of the crime, conspired to murder their alcoholic, neglectful mother and make it appear as if she had accidentally drowned while taking a bath, in order to claim the insurance money.
Eleven months after the murder, a young male came forward to the police, informing them that one of the sisters said that the girls drowned their mother.
Thus, an investigation began that included testimony gained when the young man was wired for audio and video, assessment of text messages and internet searches on a computer they owned, and interviews of their friends.
[6] By 2002, her daughters came to resent the amount of money that their mother spent on alcohol and wished that they had some of the things that their friends had like "swimming pools and clothes", which they thought would make them more popular.
[1] The friends remained steadfast in their support of the sisters and did not alert their parents, the police, or other authority figures about the crime.
[10] During lunch time on January 18, 2003, the sisters began giving their mother liquor in order to get her drunk.
After having killed their mother, Sandra and Beth went with their friends to a nearby restaurant both to celebrate their victory[9] and create an alibi.
[10] Analysis of bodily fluids disclosed very high levels of alcohol (around 400 mgs%) and drugs, including codeine and acetaminophen.
[15] About eleven months after Andersen's death, at a party, one of the girls spoke to a young male friend about the crime.
[7]: 8–13 The defendants, who came to be known as the "bathtub girls", were arrested on January 21, 2004[7] and initially placed in separate youth correctional centres.
[13] A computer was seized from the girl's residence and chat messages were found regarding the preparations, plans, and enactment of the murder.
[18] In his decision about the case, Justice Bruce Duncan stated that the girls grew up in a poor, depressing and degrading home atmosphere, even though their mother earned a good income.
[15] A young man, Beth's boyfriend, was convicted for conspiring to murder her mother and covering up the crime, based upon chat logs between him and the sisters.
They are also required to report all criminal proceedings to the Law Society of Ontario, which could result in a hearing to determine if they meet ethical and professional standards.
[16] In 2008, journalist Bob Mitchell wrote the book The Class Project: How to Kill a Mother – The True Story of Canada's Infamous Bathtub Girls.
[1][21] Linda Andersen's murder case was broadcast on the Australian television series Deadly Women in 2010.