An infant suffered extensive brain injuries after his father either shook him or slammed him on to a surface, the High Court at Rotorua has been told.
Robert Haami Boynton, 39, from Matahi Valley, is on trial accused of wounding his 4-month-old son with intent to cause grievous bodily harm, a charge each of assaulting the child with intent to injure and assaulting the child.
He has also pleaded not guilty to one charge of assaulting his former partner with intent to injure, two charges of assaulting her and one charge of attempting to pervert the course of justice.
The offending is alleged to have been committed between October 1, 2009 and May 18 last year at Whakatane, Matahi Valley, Rotoiti, Nukuhou and Auckland.
Boynton has pleaded guilty to one charge of assaulting his former partner.
Tauranga Crown Solicitor Greg Hollister-Jones told the court today that Boynton had been in a relationship with 16-year-old Ngarangi Wickliffe since late 2009 and assaulted her on several occasions, including while she was pregnant with Boynton's child.
Mr Hollister-Jones said Ms Wickliffe suffered several black eyes and a bloody nose at the hands of Boynton.
On January 2 last year, Ms Wickliffe gave birth to a boy.
The Crown alleges Boynton started assaulting his infant son because he couldn't cope with him crying.
In a brief opening statement Boynton's lawyer, Tony Rickard-Simms, said Boynton was no angel but denied assaulting his child and the other assaults on his former partner.
The trial before Justice Ailsa Duffy is expected to take two weeks.