The teenager charged with kicking a policeman in the face was controversially granted bail this week despite evidence showing he held a grudge against police and was "biding his time" at getting back at them.

The 17-year-old, who cannot be identified, is charged with assaulting police – an offence that carries a mandatory jail term of six months – after he allegedly kicked the officer at Highpoint shopping centre on Boxing Day.

The police officer who was assaulted at Highpoint on December 26, 2017. Credit:Police Association

During his bail application in a children's court this week, an investigating detective said the teenager had previously spoken online about planning retribution against police as payback for his arrest in 2016 on other offences.

"He harboured a hatred towards police and he stated he had been biding his time," the detective told the court on Tuesday.