Parole Board chairman Sir Ron Young today said reoffending like Wilson's was "extremely rare and deeply concerning".
As a result, he had commissioned an independent review of the board's involvement with the killer prior to his release.
Young said the full findings of the review would be released publicly, once Tuxford's family has had an opportunity to receive them and ask any questions.
"Her sexual violation and murder was tragic ... and appalling," he said.
"I am acutely aware of the tremendous hurt that Nicole's loved ones must feel.
"Today I am also thinking of the family of Kim Schroder."
Young said when Wilson was released the board had decided he could be managed on conditions in the community.
"The decision was made by a panel of five experienced board members and based on extensive information, including psychological opinion," he explained.
After Wilson was released he attended a monitoring hearing and the board agreed he was doing well.
"The board can only legally hold monitoring hearings for up to a year after release," said Young.
"Thereafter, the board could only have had further involvement with [Wilson] if a recall application was made by police or Community Corrections, on the basis that his behaviour deteriorated, posing an undue risk."
A recall application was made after Tuxford's death.
Prior to that, no recall applications were made to the board regarding Wilson.
Bain, who was Wilson's cellmate at Christchurch Men's Prison, was "shocked to the core" to hear his groomsman had committed a second murder.
His long-term advocate Joe Karam said Bain was distressed by the incident.
He thought Wilson was managing life well.
According to Karam at the time of the wedding, Wilson was Bain's best and oldest friend.
The pair were two of the longest-serving inmates in their section of the prison.
"They sort of naturally became ... very close," Karam told the Herald.
"The single person he [Bain] has spent the most time with over the past 18 years is Paul Wilson."
In April last year Wilson lay in wait for Tuxford at her Merivale home and pounced on her when she entered the property.
Her screams were heard by neighbours as he overpowered her and took her captive in a spare bedroom. He pulled the curtains and shut the door.
An electrician then turned up for a scheduled appointment and walked around the house trying to see if anyone was home.
Tuxford tried to fight Wilson off and bite him, while he punched her in the face.
Trying to silence her and keep from raising the alarm with the electrician, who could hear muffled noises coming from inside the house, Wilson gagged her with a scarf.
He then strangled her before he slashed her throat multiple times.
Hours after Wilson appeared in court for the first time in relation to Tuxford's brutal murder, his first victim's father died suddenly.
Kimberly Schroder's father Gary, 67, died in a suspected suicide.
Wilson was 31 when he killed Schroder, his girlfriend at the time.
He went to her flat and tied up her male flatmate.
When Schroder came home he cut her hands during a confrontation then cut off her jeans and raped her.
He then stabbed her in the neck.
Wilson was sentenced to 15 years non-parole, though on appeal that was reduced to 13 years.
His parole was granted at his fifth time of asking in December 2010, with his behaviour described as "exemplary and faultless".
Wilson was released in January 2011 into a residential programme which included at least one year of intensive therapy.
