A man has been placed on a community based order after using a device to track his ex-partner.
The man, who cannot be named to protect the victim, appeared in Mandurah Magistrate's Court on Tuesday and pleaded guilty to attaching the device under the victims car.
An investigative officer said the device was only active for a week before it ran out of battery, but it is not known how many times it was used to track the victim during that period.
The man also followed the victim on one occasion from Mandurah to Fremantle.
Magistrate Anne Longden said the offence was "sinister".
"He didn't know it was illegal to attach a device sneakily in the middle of the night to his ex-partners car?" Magistrate Longden asked the man's lawyer.
"I find that hard to believe."
Based on evidence presented to the court, Ms Longden accepted that he was acting out of concern for his children, but said the offence was too serious to be dealt with by a fine.
The man was ordered to serve a nine-month community based order under supervision.
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