The scheduled Wednesday execution of a convicted cop killer that would have used up the state 's last dose of a lethal injection drug has been halted by the highest criminal appeals court in Texas . The Texas Court of Criminal Appeals ruled to stop the scheduled execution of 55-year-old Randall Wayne Mays late on Monday . Mays was convicted of murder after a shootout in 2007 left Henderson County Sheriff 's Office Investigator Paul Steven Habelt and Deputy Tony Price Ogburn dead . Scroll down for video . Randall Wayne Mays , 55 , was due to be executed on Wednesday but a Texas appeals court put a stop to it . Mays ' punishment would have used up the Texas Department of Criminal Justice 's last does of pentobarbital . The death chamber where executions take place is located in the Walls Unit in downtown Huntsville , Texas . The court agreed with Mays ' lawyers that additional review is needed to determine if he is mentally competent for execution . His punishment would have used up the Texas Department of Criminal Justice 's last dose of pentobarbital . The drug is used for lethal injections and it is now difficult to obtain for capital punishment . Thanks to the delay , Texas has enough pentobarbital for its next scheduled execution on April 9 . The state has at least three other executions on the calendar for April . Mays was going to receive a lethal injection . The delay means Texas ' next execution can go on as planned . As a result of this order , Mays ' case will be sent back to Henderson County . An expert will need to determine whether he 's competent to receive the death penalty . The Eighth Amendment bars the execution of a person who does not understand that his execution is imminent and does not understand why he are being executed . The state believes Mays was aware of the execution and why it was going to happen . Texas prison officials , like those in other death penalty states , have found it increasingly difficult to find suppliers to provide drugs intended for capital punishment use . The state 's penultimate portion of pentobarbital was used in the execution of a Mexican hit man who was convicted of beating and strangling a San Antonio woman . Manuel Vasquez killed the woman because she did n't pay a ten per cent tax on her illegal drug sales . Vasquez was executed on March 11 and he was the fourth Texas inmate put to death this year .
Randall Wayne Mays due to die Wednesday for killing two in shootout . Henderson County Sheriff 's Office Investigator Paul Steven Habelt and Deputy Tony Price Ogburn were both fatally shot in 2007 . Appeals court ruled Mays might not be mentally competent for execution . His death would have finished Texas ' supply of injection drug pentobarbital . At least four executions are scheduled for next month with fourth on April 9 .