A Texas man has been sentenced to decades in prison after admitting to killing his ex-girlfriend and attempting to cover up the crime. The case, which shocked the Midland community in 2023, has now reached a conclusion with a lengthy prison term for the accused.
Guilty Plea in Midland County Murder Case
Mario Juan Chacon, 27, pleaded guilty to one count of murder and one count of tampering with evidence in connection with the death of 20-year-old Madeline Pantoja.
According to the Midland County District Attorney’s Office, the plea was entered on Friday in the 142nd District Court. Judge David G. Rogers sentenced Chacon to:
- 35 years in prison for murder
- 20 years in prison for tampering with evidence
The sentences will run concurrently, meaning he will serve both at the same time.
Victim Last Heard From in May 2023
Madeline Pantoja was last heard from on the night of May 10, 2023. Friends told investigators they had spoken to her that day. Her final known message involved plans to go swimming at her apartment complex the next day.
When friends could not reach her, they went to her apartment at the Palladium Museum Place Apartments in Midland. No one answered the door.
On May 11, police responded to a welfare check requested by her brother, but again received no response. The following day, officers returned after someone reported hearing a woman’s voice inside the apartment.
Disturbing Signs Inside the Apartment
When officers finally entered the apartment, they found troubling signs. According to court documents:
- A mop and dirty bucket of water were near the front door
- The floor was extremely sticky, as if heavily cleaned
- A coffee table was missing
- The victim’s dog had been left without food or water
- Doors showed damage, including holes and hair attached to one
- A large red stain was found on a bedsheet
Investigators suspected an attempt had been made to clean up a crime scene.
Chacon’s Changing Story
Police interviewed Chacon multiple times. During his first interview, he claimed he last saw Pantoja on May 9 and last spoke with her by phone on May 10.
Later, he changed his story and admitted he had been near her apartment complex the night she disappeared. Surveillance footage, traffic cameras, and cellphone location data placed his vehicle near the complex between 12:26 a.m. and 3:37 a.m.
During a third interview, detectives confronted him about inconsistencies in his timeline. Shortly after, investigators began focusing on specific rural areas based on phone data.
Discovery of Human Remains
On May 20, 2023, search teams using mapped cellphone records located human remains in a rural area of Midland County near East County Road 190 and South County Road 1138.
The remains were identified as Madeline Pantoja, partly through jewellery found with the body. Authorities later confirmed she had died from strangulation and suffocation. The autopsy also revealed she had been beaten during the attack.
Chacon was arrested later that same day.
Indictment and Final Sentencing
Chacon was formally indicted for murder in July 2023 and later indicted for tampering with evidence in November 2025.
He remained in the Midland County Jail on a $3 million bond until his recent guilty plea. He will now be transferred to the Texas Department of Criminal Justice.
Under Texas law, he will become eligible for parole after serving at least half of his sentence. He will also receive credit for time already spent in jail.
