The Crown summary of facts reveals Izett ended up in a police cell at Tauranga station on February 5, 2019, following his arrest on The Strand where he was found in an agitated state after he had consumed methamphetamine.
Izett was detained under the Mental Health Act as his behaviour that night was "very agitated" and he was not making sense, the summary said.
He would not follow police instructions and was not making any sense, and a police doctor diagnosed Izett as suffering from "excited delirium".
Due to concerns for Izett's welfare a decision was made to remove him from the police cell and take him to Tauranga Hospital.
The assault victim was part of the police extraction team all wearing protective gear.
Izett was ranting and his sentence structure was "incoherent" and during his removal from the police cell, he punched the female officer in the head two or three times.
He also grabbed her helmet and tried to wrench it from her head, which involved the victim's head being violently moved from side to side causing her to be "thrown around like a rag doll".
The severe concussion resulting from Izett's assault meant his victim was on light duties for nearly a year.
She also suffered memory loss, headaches, sensitivity to light, fatigue, and optic nerve damage.
Izett pleaded guilty to a further charge of injuring with intent with reckless disregard for the safety of others.
He was sentenced by Judge David Cameron immediately after the plea.
Judge Cameron, who read the summary of facts to the court, said a concurrent prison term of six months was appropriate to hold Izett accountable and to also deter him from committing this "totally unacceptable violent behaviour" again.
The six-month sentence will be served alongside his 17-year sentence for murdering 2-year-old Nevaeh Jahkaya Whatukura Ager.
The slain toddler was found dead on March 21, 2019, not far from the Little Waihi home she shared with Izett and her mother Alyson Ager in Maketū.
Izett violently beat Nevaeh and placed her naked body face down in the water on the mudflats on the Little Waihi estuary before placing two large rocks on her top.
At his trial, pathologist Rexson Tse gave evidence that Nevaeh sustained multiple bruises and abrasions to almost all of her body, caused by a weapon or weapons.
Tse said there could have been 70 to 80 blows to the toddler's body, including at least 10 or possibly up to 20 to her head and there was also a torn ligament in her neck.
The jury also heard that Izett had binged on significant amounts of cannabis and P in the days before his daughter's death.
Izett was found guilty in the High Court at Rotorua in October last year despite his plea of not guilty by reason of insanity.