The murderer, whose maiden name was Scutter before marrying Simon Patterson in 2007, was secretly nicknamed 'Scutter the Nutter' among her training group.
'Something was not quite right, she was a bit strange,' a coursemate who asked not to be named told
The Herald Sun.
The source described Patterson as 'super secretive' about her life, and claimed she was also dubbed 'crazy Erin' by her peers and that 'she would say some weird off-the-cuff things'.
'She wasn't a nice person, she just wasn't someone you connected to,' they said.
Another colleague, who had managed Patterson, said she was counselled about her dishevelled appearance and that concerns were raised by a workmate that she had placed a blade from a pencil sharpener in a banana.
Patterson worked in the Southern Flight Information Region, based in Melbourne, from February 12, 2001, until November 28, 2002.
She was fired after Airservices Australia management began to suspect she was leaving work early while claiming the time.
CCTV from the car park confirmed management's suspicions, but Patterson lied until she was shown the incriminating footage.
The former colleague described Patterson as 'manipulative', 'aggressive' and branded her a 'pathological liar'.
It's understood Patterson 'wrapped [men] around her little finger' and had been pursued by several staff members.
Not long after Patterson left the job in 2002, she was slapped with a long-term licence ban after driving drunk and fleeing the scene of a car crash.