SALEM – One of the seven inmates involved in an uprising that resulted in five guards being injured in June is headed to prison for up to four years.After pleading guilty in Salem Superior Court Wednesday morning, Jurrell Laronal, 22, of Dorchester, changed his plea to guilty on two counts of assault and battery with a dangerous weapon, assault and battery with a dangerous weapon, causing serious bodily injury, assault with a dangerous weapon and malicious destruction of property in connection with the June 7 attack on the guards at the Middleton Jail.He was sentenced to serve not less than two and a half years and not more than four years in state prison and placed on probation for six years by Judge David A. Lowy.Assistant District Attorney Michael A. Patten said all seven inmates were in a segregation unit at the jail and were let out of their cells to take showers. They apparently crawled out from underneath the shower doors and attacked the two guards in the unit after grabbing the shackles and handcuffs that had just been removed from them.They allegedly smashed a computer, computer keyboard, monitors and took brooms from a storage closet and began swinging them at the guards as the officers radioed for help.Other corrections officers quickly responded to the backup call and subdued the inmates in less than five minutes.Two of the guards received head wounds and another had wounds to his head which had to be stapled closed.Laronal is the second of the seven inmates to confess to his joint participation in the jail melee.Five others, Angel Andrades, 23, Juan Rivera, 24, formerly of Lynn, along with Miguel Diaz, 21, Raul Carraquillo Llanos, 35, and Alexis Maldonado, 29, remain in custody awaiting trial on the case.Another participant, Eddy Lopez, also known Miguel Torres, 30, of Lawrence, pleaded guilty to his role earlier this summer.Laronal has been serving a two year jail sentence on firearm charges out of Suffolk County on another case, but the state prison sentence imposed effectively erases that jail term.Laronal will begin serving the state time and probation term immediately, Lowy ordered.Patten suggested that the sentence imposed should be after he completes his jail sentence, saying it was based on the “facts of the case,” and that the punishment is “necessary,” for his conduct.But defense lawyer John T. Haggerty, asking for the 30-month sentence, pointed out to Lowy that his client has “accepted responsibility.”Lowy acknowledged that the officers? safety was “jeopardized,” as he handed down his punishment, but warned Laronal if he does not conform to the requirements of his probation terms, he faces up to 15 years in prison.When Laronal gets out of prison, he must be employed or have five pending job applications on file while completing his probationary term.