A Queanbeyan Magistrate handling a case he described as "terrorists terrorising innocent kangaroos", said he had to hand down a "ridiculously lenient" penalty for a man involved because "his hands were tied" by a district court decision.
A Tiktok video showed Peter McMinn, 21, and four others killed kangaroos by running them over in a ute at Royalla, just outside of Canberra, in April 2020.
Any of the kangaroos that survived being hit were finished off by the group with a hammer.
The court heard the group "burst out laughing" when one kangaroo was run over.
Court documents showed they targeted a joey, with a voice heard on the video saying:
"Get the f***ing baby, I want to bang it over the bulbar."
Magistrate Roger Clisdell said the group's behaviour "is despicable beyond contempt".
"To enjoy that slaughter is inhumane," he said.
"This was a collective group of teenagers who behaved like little terrorists terrorising innocent kangaroos."
'I should be locking Mr McMinn up for a substantial time': Magistrate
Magistrate Clisdell originally handed prison sentences to the other four in the group who were aged under 18 at the time, but they were cleared of any conviction on appeal in the Queanbeyan District Court.
McMinn pleaded guilty to one charge of torture, beating and causing the death of an animal.
Magistrate Clisdell told the court "I should be locking Mr McMinn up for a substantial time".
McMinn was convicted and handed a community corrections order with a good behaviour bond for two years.
Magistrate Clisdell said the decision was "ridiculously lenient", but the district court's decision to clear the others' convictions meant he had no other choice.
"In effect, my hands have been tied by the decision of the district court," he said.
"As much as it goes against every grain in my body, I think I need to treat McMinn in the same fashion [as the other offenders]."