( CNN ) -- One day before convicted school shooter T.J. Lane jumped a fence and fled an Ohio prison , staff at that prison segregated an inmate and warned officials about an escape plot there , the head of the prison guards ' union said Friday . Christopher Mabe , the president of the Ohio Civil Service Employees Association , told CNN the segregated inmate was not T.J. Lane , the 19-year-old who killed three students at a high school cafeteria east of Cleveland in 2012 . Mabe could not say if the segregated inmate was one of the other two prisoners who escaped with Lane from the Allen Oakwood Correctional Institution in Lima , Ohio , on Thursday night . What Mabe did say is the inmate was segregated Wednesday and that prison staff filed documentation that day about the escape plan . A union spokeswoman provided CNN with a copy of that report Friday night . It read : `` ( A corrections ) officer ... was approached in the OCF cafe by an inmate who wanted to advise me that ( another ) inmate ... had told him that he was planning on escaping and finding ( a corrections officer ) and killing her . I immediately reported this to Lt . Brown . '' Sally Meckling , the union spokeswoman , acknowledged that the inmate who allegedly was planning to escape was segregated at the request of a corrections officer . No one has tied this reported plot to the escape of Lane and the two others . `` We are not making that direct link , '' Meckling said . `` But we do think more precautions should have been made . '' The Ohio Department of Rehabilitation and Correction is looking into this report , department spokesman Joellen Smith said Friday . All three escapees are now back in custody . Lane was found outside a church 100 yards away from the prison shortly after 1 a.m. Friday . Lane has never explained his motive for the February 27 , 2012 attack in which he entered the cafeteria with a .22-caliber gun and randomly started shooting , killing three students . Convicted school shooter back in custody . Still , while the manhunt is over , the fact that Lane and the others managed to escape has stirred big questions . Some wonder why Lane was n't in the maximum-security part of the prison , even though he was serving consecutive life sentences without the possibility of parole for the Chardon High School shooting -- an incident for which he 's never shown remorse . `` That is something we have to sit down and take a look at , '' Warden Kevin Jones said . Ohio 's Correctional Institution Inspection Committee , which evaluates the state 's correctional facilities and reports to the legislature , most recently reported on the Allen Oakwood Correctional Institution last April . It found `` ongoing concern regarding the Protective Control unit , '' while also noting there has been improvement in that unit and `` fewer security management concerns . '' Their overall rating for the facility was `` good '' -- the second best grade out of four . Ohio school shooter shows no remorse at sentencing . CNN 's Ed Payne , Cristy Lenz and Kevin Conlon contributed to this report .
NEW : Report : An inmate told a guard about another inmate 's escape plan . NEW : Union official : `` We are not making ( a ) direct link '' to T.L . Lane 's escape . NEW : Inspection committee gave a `` good '' rating to the Lima , Ohio , prison . Lane , 2 others briefly escaped , only to be caught soon thereafter .