19-year-old man pleads guilty to murder in Green Valley Ranch fire that killed 5 family members

Gavin Seymour faces between 16 and 40 years in prison on the single count of second-degree murder
Green Valley Ranch arson august 2020
Suspected Arson Fire - Green Valley Ranch
Posted at 8:53 AM, Jan 19, 2024
and last updated 2024-01-19 19:25:34-05

DENVER — A 19-year-old man pleaded guilty Friday to second-degree murder for starting a house fire that killed five people in Denver’s Green Valley Ranch neighborhood more than three years ago.

Gavin Seymour pleaded guilty in the Aug. 5, 2020, fire that killed five Senegalese family members in a home on Truckee Street. He faces between 16 and 40 years in prison on the single count of second-degree murder. Dozens of other charges against him will be dismissed as part of the plea agreement.

"It's a step toward justice for us. It's been a long process for us going on four years now," said Ousman Ban, a member of the Senegalese community and an advocate for the family of the victims. "That is what the family is seeking, and us in the community, is getting the maximum sentence for all the suspects involved in this horrific act."

Seymour and two other teenagers — Kevin Bui and Dillon Siebert — were accused in January 2021 of intentionally setting the house on fire in the middle of the night. The trio incorrectly thought Bui's stolen iPhone was in the home and set the home ablaze as revenge, according to an arrest affidavit.

Djibril Diol, 29; Adja Diol, 23; Khadija Diol, 2; Hassan Diol, 25; and 6-month-old Hawa Baye were killed in the blaze.

Siebert, who was 15 at the time, pleaded guilty in December of 2022 to second-degree murder charge that included a sentence enhancer for using a weapon in a crime and was sentenced about two months later.

But the cases against Seymour and Bui were stalled for several months while the Colorado Supreme Court considered whether the methods used by police to identify them as suspects in the arson were legal in the first place.

A search warrant requested by the Denver Police Department in the case required Google to turn over records of keyword searches for that address within a specific time frame, likely violating the suspect's 4th Amendment rights, which protects them from unreasonable searches and seizures by the government. The state's supreme court upheld that controversial search warrant in October of last year, and the cases against Seymour and Bui were able to move forward.

Seymour faced nearly two dozen counts of first-degree murder, which carries a life sentence without the possibility of parole in Colorado. He was also charged with multiple counts of attempted murder, arson, burglary and assault, but the charges were dismissed because of the plea agreement. His sentencing is set for March 15 at 1 p.m.

The criminal case against Bui is still pending.

The family, Ban said, "will never see the justice they want. They just want closure."

Denver7's Russell Haythorn contributed to this report.

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