Two men have been sentenced over a “violent and destructive riot” at Albany Regional Prison in which WA Police negotiators were called in as back-up. Bolton Ivan Vladimirovich Mamkin, 25, pictured, and Keith Ronald Clinch, 25, last week appeared in Albany District Court, where they were both convicted of riotous assembly within a prison, aggravated assault causing bodily harm to a prison officer, and making a threat to unlawfully injure a person. Mamkin, already a long-term sentenced prisoner, received an extra 15 months imprisonment for the three offences. He has been in prison since 2015 and is serving a total sentence of more than 10 years. Clinch, who has been held in custody since December, received a 17-month sentence. In handing down each man’s sentence, Judge Mark Herron described the riot that placed the maximum-security prison in lockdown as “violent and destructive”. The “out-of-control” incident lasted three hours and only ended after each offender was “forcibly apprehended” by riot officers. At the time of the incident, the Advertiser reported WA Police Force negotiators had been called in to help quell the riot. State prosecutor Sarah Jessup told the court the riot took place on March 21 last year after a co-offender, Jay Lynchfield, was denied medication and became abusive towards prison officers. Lynchfield has also received jail time for his involvement in the riot. “The matter escalated to a confrontation in the main area of the B-yard,” she said. “At this point, each of you ... became involved in a confrontation with prison officers, and the situation quickly got out of control, leading to the prison going into lockdown.” While he was holding sharp pieces of PVC piping, Mamkin threatened staff, saying: “Anyone who steps in this yard and is wearing blue is going to get stabbed”, Ms Jessup told the court. For three hours that night, concrete, bricks and other objects were thrown at prison officers. A male prison officer was injured. Ms Jessup told the court the estimated cost of damage caused in the riots was more than $4000. The court was told the riot happened about five months after Mamkin “bashed” another prisoner in November 2019, causing serious facial injuries. During sentencing for the 2019 assault, a District Court judge said it would normally take something like a “motor vehicle crash” to inflict the sort of injuries sustained by his victim. In court last week, Judge Herron said the 2019 assault did not aggravate the severity of the riot offence, but it did highlight the risk of re-offending. “You have a propensity for violence, particularly in a prison setting, and (it) underlines the need for personal deterrence and the need for a protection of the prison population,” Judge Herron said.