UPDATE March 12, 2026: Mumma has been transported to the Jefferson County Jail. His first court appearance will be on March 13, 2026:
Watch via livestream HERE
March 11, 2026 – GOLDEN, Colo. – District Attorney Alexis King has announced that the Grand Jury for Jefferson and Gilpin counties has returned a two-count indictment against Brandon David Mumma in the death investigation of thirty-four-year-old Denver resident Jax Gratton. Mumma, who is believed to be the last known individual to be with Gratton, faces one count of Tampering with a Deceased Human Body (F3) and Tampering with Evidence (F6).
The indictment alleges that Gratton and Mumma, who were engaged in a consensual intimate relationship, entered an office space located at 9655 West Colfax at 10:41 P.M. on April 15, 2025. According to the indictment, a male friend arrived at 12:14 A.M. and exited the unit with Mumma at 1:43 A.M., leaving Gratton alone and asleep under the influence of drugs. Based on multiple security cameras that recorded activity in the entryway, stairway, and throughout the common areas of the building, nobody entered or exited the doors of Unit G until Mumma returned at 5:55 A.M.
According to the indictment, Gratton’s last active session on her phone was in the early morning hours of April 16, 2025, and used an IP address associated with 9655 West Colfax Avenue in Lakewood.
The indictment further alleges that when Mumma entered the unit at approximately 5:55 A.M, he remained inside until 6:57 A.M., when he moved his vehicle to the north side of the building. Mumma then entered the building and returned with trash bags, which he threw into a dumpster. Mumma then left the area.
On June 6, 2025, Gratton’s body was located between the buildings of 9655 and 9699 West Colfax Avenue. The reporting party accessed this area using a door into the area from 9699 W. Colfax Avenue, which at the time was vacant. No comparable door exists into the area from 9655 West Colfax Avenue. The area where the body was located is a narrow, four-foot-wide space that is inaccessible to the public. It is locked from both ends, requires a key for entry, and features a solid gate on the south side that completely obscures the area from view.
Gratton was found wearing the clothes she had on as she left her apartment on April 15, 2025. She was found lying on her side, and a grate from an air conditioning unit was on top of Gratton’s lower body. There was a significant dent on top of the air conditioning unit located directly below the north half of the second-story window of 9655 W. Colfax Avenue, Unit G.
By the time the unit was searched on May 29, 2025, the furniture from April had been removed from the office. None of Gratton’s personal belongings, including her cell phone, were ever recovered.
The two-count indictment alleges that on or about April 16, 2025, Mumma removed Gratton’s deceased body, as well as her personal belongings and other evidence of her death, to avoid detection by the police.
On Monday, March 9, 2026, the grand jury indictment was presented to the First Judicial District Court, and an arrest warrant was signed for the arrest of Brandon Mumma on the charges of Tampering with a Deceased Human Body and Tampering with Evidence.
The second male, who was present in the unit on April 16, 2025, between the hours of 12:14 A.M. and 1:43 A.M., and remained cooperative with law enforcement, is not named in the indictment and is not believed to have participated in the destruction or removal of any evidence associated with Gratton.
Just a few hours ago, Mumma was taken into custody in Summit County, Colorado. He has a $100,000 cash bond on the indictment. Some details are still being developed. We expect his first court appearance will be tomorrow, in Summit County. Any change to that information will be communicated.
Statement from District Attorney Alexis King:
“The allegations in this indictment follow a months-long, collaborative investigation by the Lakewood Police Department and the Denver Police Department. I want to commend the Lakewood agents whose persistence made this indictment possible, and I thank the victim’s loved ones and the community for their patience as we pursue justice. From the outset, law enforcement and prosecutors have treated this matter with the utmost seriousness, and we remain committed to prosecuting those named to the full extent of the law.”
Pursuant to our ethical rules, no additional information or further public comment will be provided by this office during the pendency of the case.
The charges are merely legal allegations, and Mr. Mumma is presumed innocent of the charges against him unless and until he is proven guilty beyond a reasonable doubt.
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