The guilty plea ended a three-year Oklahoma murder case in which prosecutors had previously sought the death penalty.

NORMAN, Okla. — Chace Cook pleaded guilty to first-degree murder and was sentenced to life in prison without the possibility of parole for killing 18-year-old Madeline “Maddie” Bills, bringing a closely watched Cleveland County case to an end more than three years after the Moore High School senior was found dead in her family’s pool house.

The July 28 plea replaced the possibility of a capital trial that could have exposed Cook, now 23, to a death sentence. Prosecutors had formally sought capital punishment after alleging that Bills was sexually assaulted and strangled in April 2023. Cook admitted first-degree murder with malice aforethought and waived his right to appeal as part of the agreement. He also pleaded guilty to separate offenses committed while he was jailed awaiting resolution of the murder prosecution. District Attorney Jennifer Austin said the plea and sentence gave the case a final legal resolution, while acknowledging that no punishment could restore Bills’ life or erase the loss suffered by her family.

The sentence marked a sharp turn from the path prosecutors had followed for much of the case. In January 2024, then-District Attorney Greg Mashburn filed a bill of particulars announcing that the state intended to seek the death penalty. Prosecutors described the killing in court filings as especially heinous, atrocious or cruel and said the decision to pursue capital punishment followed a review of the evidence and discussions with Bills’ family. Cook later entered a not-guilty plea and remained on course for trial. By accepting the 2026 plea, prosecutors secured a sentence that bars parole and avoided the uncertainty and further proceedings that would have accompanied a capital prosecution.

Bills was found dead April 22, 2023, in a converted pool house that served as her bedroom behind her family’s home in Moore. The Oklahoma medical examiner determined that she died from strangulation and classified her death as a homicide. Investigators also documented evidence of sexual assault. Cook, who had previously dated Bills, was arrested near Chicago on May 1 after authorities began searching for him. He was returned to Oklahoma and initially faced charges of first-degree rape and first-degree murder. The murder case ultimately became the charge at the center of the plea agreement that resulted in his life-without-parole sentence.

The prosecution was supported by a combination of surveillance, digital and biological evidence described in police affidavits and court testimony. Investigators said video from near the Bills home showed a person climbing a fence into the family’s backyard during the early morning hours when authorities believed the crimes occurred. Police also traced Cook’s cellphone to the area. A Ford Fusion previously associated with Cook was recorded near the property, according to investigators. Authorities said DNA recovered during the investigation matched Cook. At a preliminary hearing in December 2023, a judge found probable cause to send the case toward trial after hearing testimony about the evidence collected by detectives.

Investigators also recovered a video from Cook’s phone that authorities said showed him sexually assaulting Bills while she appeared unconscious. The allegation was one of the most serious elements of the original case and formed part of the basis for the rape charge filed after Cook’s arrest. Court testimony later described additional material recovered from his phone, including internet searches investigators considered relevant to the assault and killing. Those allegations were publicly presented while Cook still faced trial and were not supposed to be treated as proven facts at that stage. His eventual guilty plea was specifically to the murder charge, along with separate jail-related crimes.

Police said Bills had expressed fear of Cook before her death. According to an affidavit, she told friends that she was scared of him and was considering sleeping inside the main family residence rather than in the detached pool house because she feared he could come to harm her. Investigators said Cook initially offered an account that placed him in Galveston, Texas, for training connected to becoming a Navy SEAL. Authorities challenged that account after examining travel times and digital evidence they said placed his phone near Bills’ home. The police interview ended after Cook requested an attorney when investigators confronted him with evidence they said contradicted his story.

The timing of Bills’ death intensified the loss for her family and school community. She was a Moore High School senior with a 4.0 grade-point average and was approaching graduation. A standout basketball player, she had signed a letter of intent to play women’s basketball at Northeastern Oklahoma A&M College in Miami, Oklahoma. She was also a member of the Osage Nation. Family members repeatedly asked that public attention focus not only on the circumstances of her death but on the life she had built. They described her as a determined athlete and a person who brought kindness, energy and encouragement to those around her.

During the sentencing proceedings, Bills’ relatives again spoke about the space her death left in their lives. The District 21 District Attorney’s Office said family members remembered her as a light and described her absence as something felt in daily moments as well as in the future she never had the opportunity to experience. Their statements echoed what relatives had said soon after the killing, when they emphasized Bills’ generosity, competitiveness and effect on friends and family. The family also established a scholarship in her memory, an effort intended to connect her name with the educational and athletic promise that had defined her senior year.

Cook’s plea also resolved criminal allegations arising during his incarceration. Prosecutors said he pleaded guilty to possessing contraband in jail and received a 20-year prison sentence on that count. He also pleaded guilty to assault and battery stemming from a 2026 jail incident and received six months in the county jail. The sentences were ordered to run concurrently, meaning the life-without-parole murder sentence controls how long he will remain imprisoned. By waiving his appellate rights under the agreement, Cook also gave up a normal avenue for challenging the convictions produced by his pleas.

The case had moved through several major stages before the agreement was reached. After the 2023 arrest and charges, a judge heard evidence at a preliminary hearing and ruled that prosecutors had shown sufficient probable cause for the case to continue. Cook formally pleaded not guilty in February 2024. The state’s death-penalty notice meant later proceedings would have required litigation over both guilt and punishment had the case reached a capital trial. Instead, the guilty plea eliminated the need for a jury to decide those questions and guaranteed that Cook would remain incarcerated for life without an opportunity for parole.

Austin said prosecutors, victim advocates, support staff and Moore police had remained involved throughout the lengthy proceedings. The sentencing closes the criminal prosecution over Bills’ killing, more than three years after her death and after a case that moved from an initial rape arrest to a first-degree murder charge, a death-penalty filing and ultimately a negotiated guilty plea. With Cook’s appeal rights waived and his life-without-parole sentence imposed, no further trial is scheduled in the murder case.

Author note: Last updated August 30, 2026.