Name suppression for Tareha was lifted when he admitted the four charges of unlawful sexual connection, injuring with intent, two counts of burglary and two charges of assault with intent to cause sexual violation.
The son said the attack had left a lasting impact on the extended family, including his mother's grandchildren.
The elderly woman has been a widow for 20 years, and has three children and eight grandchildren, who rallied around her, sending cards, messages of support and flowers after the assault. "She is still nervous to go outside and locks all the doors and windows now."
He said his mother has continued living at her Frimley home, after she locked her doors and "sought solace" in her bed for 5 hours after the assault.
Tareha was arrested on November 15 last year, after a week-long police manhunt, and at the time Detective Senior Sergeant Dave de Lange said that the arrest came about after a team effort between police and a shocked community.
"This was a particularly nasty crime and the arrest has been very rewarding for the staff involved. I acknowledge the long hours put in by our staff who have been working constantly since the attack occurred."
Justice Simon France remanded Tareha in custody until sentencing at the High Court in Napier on September 23, and also ordered two psychiatric health assessments for the prisoner.