Because of the mosque attacks, a Super Rugby match between the Highlanders and Crusaders set to take place at Forsyth Barr Stadium on March 16 was cancelled.
"Many people took to the streets in the university area to party and consume alcohol," court documents said.
Police, who were patrolling areas around the mosque, were on Castle St, clearing up to 200 people from the road.
At the intersection with Dundas St, the defendant approached their vehicle and shouted his racist message.
"He yelled this repeatedly amongst the crowd of people on the street," police said.
The teen was firmly told that his comments were "inappropriate and insensitive".
However, the defendant was unapologetic, stating he was entitled to his opinion and freedom of speech.
He accused officers of trying to intimidate them and accused them of being "right-wing fascists".
While this discussion was ongoing, three women told police that earlier in the evening the teenager had repeatedly shouted "f*** the Muslims".
Others on the street began to abuse the defendant for his comments and police arrested him.
Defence counsel Andrew More told the court his client's father was at yesterday's hearing and had been "surprised and disappointed" in his son's behaviour.
Judge Michael Crosbie called it "no more or less than overt racism".
He refused to sentence the teenager on the spot because he wanted to know what the repercussions would be with the University of Otago.
A university spokesman said any students who committed criminal offences were dealt with once any court process had concluded.
The Code of Student Conduct says: "This statute gives the university the power to suspend or exclude students from the university, or to fine and impose community service penalties, for offences committed on or off campus."
The defendant, who did not return calls yesterday, will be sentenced in June.
