Two teens have now pleaded guilty to first-degree murder in the death of Fairfield High School Spanish teacher Nohema Graber. Willard Miller and Jeremy Goodale entered guilty pleas Tuesday in Jefferson County Court in Fairfield, a town of about 9,400 people located about 100 miles southeast of Des Moines.Miller, whose trial was supposed to start on Friday in Council Bluffs, appeared first Tuesday, followed by Goodale. Graber’s body was found in a Fairfield park on Nov. 3, 2021, hidden under a tarp, wheelbarrow and railroad ties. Prosecutors say she had been beaten to death with a baseball bat. Graber was 66.Both Miller and Goodale were charged with first-degree murder.Miller and Goodale were 16 at the time. Miller is now 17. Goodale is now 18.Court documents revealed that Miller was upset about a bad grade given to him by Graber.Prosecutors say both of the teens struck Graber with a baseball bat and destroyed evidence in the case. Goodale told the court he was the lookout while Miller hit her first, after Miller's hit with the bat did not kill her he also hit her. A witness told authorities they saw two males driving Graber's van the night of her killing near the park where she was found dead.Prosecutors agreed to recommend a sentence between 30 years and life in prison with the possibility of parole as part of an agreement with Miller. Prosecutors said they would recommend a sentence between 25 years and life with the possibility of parole for Goodale.Goodale will be sentenced on Aug. 23. Miller will be sentenced on July 5.Goodale previously agreed to testify against Miller at his trial, which was expected to begin later this week.Goodale and Miller were both charged as adults because of the severity of the crime, but they weren’t subject to a mandatory sentence of life without parole because they were 16 at the time Graber was killed. Willard is now 17 and Goodale is 18.In a statement to KCCI: Miller's attorneys say this was an opportunity for him to take accountability for his actions."Today Chaiden Miller took responsibility for his actions and started a path toward accountability. Chaiden's plea is the first step of a plea and sentencing process. "In pre-sentence investigation, Chaiden and those around him will provide details and background. We hope to better understand how a child with a history of kindness and respectful behavior ended up pleading guilty to murder. "Chaiden’s family continues to express sympathy to the Graber family."Scott Brown with the Iowa Attorney General's Office said Miller's guilty plea came just days before his trial was scheduled to start. He also said Goodale had planned to plead guilty for quite some time.Previous coverage: Court documents reveal timeline Fairfield teacher's slayingWho was Nohema Graber?Nohema Graber taught Spanish classes at Fairfield High School from 2012 to her death. She previously taught in the Ottumwa Community School District.She was 66 when she was killed on Nov. 3, 2021.Her family spoke at an emotional service days after her death. Her son Christian read from Graber's personal notebook: "We the teachers must be a positive role model for our students, and even if the students forget about my Spanish classes, I hope they remember how and why to smile in life and be honest."At the end of the service, Graber's pastor told the crowd to take comfort that she is now in heaven.Information from the Associated Press was used in this article.