"He's been interviewed by Lower Hutt police, objects have been seized as evidence including the crossbow.''
The investigation was ongoing and no decision had been made about charges, he said.
"The officer looking after that case is consulting with prosecutions as well as seeking a legal opinion before laying any charges. SPCA has been informed.''
Ms Ferrari said she was relieved that someone had owned up, but wanted to speak to him before decided whether to push for him to be charged.
``The police are going to organise a meeting,'' she said.
Ms Ferrari said she didn't know what she would say to the young man.
Moomoo was doing well, but still had a drain in place to remove fluids, she said.
"The vet is hoping that they'll be able to remove it today so that he can come home on Saturday.''
Earlier this week, Vet surgeon Dr Jonathan Bray said Moomoo was extraordinarily lucky.
"The bolt went in just above the eye but was a glancing blow across the cranium so didn't actually impact on brain tissue at all,'' he said.
"It was really just a matter of opening up the track so we could clean up the contamination so it would heal up okay.''
Dr Bray said the cat's nose and eye socket were injured, but otherwise he was "extraordinarily lucky''.
"The velocity of the bolt hitting him would have been quite frightening, so he's very brave.''
