Witchall met the 16-year-old through a mutual friend and became angry when she refused a hug.
He led her to a basement carpark and said she could only leave once they had sex. All four of his grooming victims were under 16 and Witchall bombarded them with messages until they agreed to meet.
When they did, the indecent assaults took place.
Witchall had repeatedly claimed his innocence while at Christchurch Men's Prison but he appeared to have a recent change of heart.
He told a report writer he wanted to take responsibility for his crimes but when he appeared in front of the Parole Board last month he denied that.
Witchall could not explain the mix-up. He was also "unsure" why he had refused to be interviewed by a psychologist.
A Black Power member, the prisoner had a history of non-compliance with sentences, and that attitude had endured.
Ms More noted Witchall was described as "demanding and abusive" towards staff and had lost privileges and employment in lock-up because he had damaged property and assaulted another inmate.
A Corrections officer who spoke to the board said the man's behaviour was "up and down".
Witchall was assessed as an above-average risk of sexual reoffending and a high risk for violent crimes, and because of his continued claims of innocence he had not undertaken specialist sex-offender treatment.
The decision for the Parole Board was straightforward.
"Without any rehabilitation, no release plan, and no address, Mr Witchall's risk remains undue and parole is declined," Ms More said.
He will appear before the board again in April 2023.