Erandy Elizabeth Gutierrez was furious after she received messages that alerted her to the fact that her friend had uploaded naked pictures of the pair to the social network.
She told her friend, Anel Baez, also 16, that she would be lucky to survive until the end of the year.
‘It may seem that I am very calm, but in my head I have killed you at least three times,’ Gutierrez wrote to Baez via Twitter.
Laughing off Gutierrez’s threat that she would ‘bury’ her ’before the end of the year’, the unwitting Baez invited her friend to her home in Guamuchil, Mexico to patch things up.
According to local police, Gutierrez asked to use the bathroom but instead went into the kitchen where she found the knife she used to stab her friend over 60 times.
A police spokesman explained that after the murder Gutierrez tried to clean the blood from her clothes and the weapon but was unsuccessful.
Gutierrez tried to hide her role in the murder after fleeing the scene and even pretended to grieve alongside her other friends.
But following police investigations she was eventually arrested at her best friend’s funeral – keeping the sinister promise she made to see her buried before the end of the year.