Three and one-half years after an arson fire killed five members of a Senegalese immigrant family — including a 2-year-old and a 6-month-old girl — a second suspect has plead guilty in the crime. 

Gavin Seymour, now 19 years old, pleaded guilty to second-degree murder charges in the Aug. 5, 2020 fire in the Green Valley Ranch neighborhood of Denver. In exchange for the plea, 60 charges against him were dropped, including first-degree murder, attempted murder, assault and arson.

Seymour was one of three teens who allegedly started a fire at the wrong house out of revenge for a stolen cellphone. 

Seymour now faces between 16 and 40 years in prison. He will be sentenced on March 15, according to the Denver District Attorney’s Office.

The incident began in the early morning of Aug. 5 when Seymour, Kevin Bui and Dillon Siebert — Bui and Seymour 16 at the time, Siebert 15 — allegedly started a house fire.

Siebert previously pleaded guilty to second-degree murder and has received a 10-year detention sentence: Three years in the state’s Division of Youth Services, which handles juvenile detention, and seven years in the Department of Corrections’ Youthful Offender System.

Eight people were inside the home when the fire was set. Killed in the fire were Djibril Diol, 29; Djibril’s wife, Adja, 23; the couple’s 2-year-old daughter Khadija; Djibril’s sister, Hassan, 25, and Hassan’s 6-month-old daughter, Hawa Beye. Three people survived the fire by jumping from a second-story window.

The incident sparked fear in Denver’s West African community about whether the attack was a targeted hate crime. The teenagers, later charged as adults, intended the attack as revenge for a robbery in which Bui’s phone was stolen.

However, the teens targeted the wrong house.

The Denver Police Department arrested the teenagers in January 2021. The catalyst for arrest was a Google search warrant that asked the company to turn over any searches of the specific address.

The warrant proved controversial, with the Colorado Supreme Court pausing the cases for several months while they decided the legality of the searches. 

Seymour’s attorneys argued that the warrant violated his protections against unreasonable searches and seizures.

The justices found in a split decision released in October 2023 the evidence uncovered would be admissible in court because police acted on a good-faith belief the warrant was constitutional.

“The Court recognized that police officers exercised good faith in obtaining the warrant that led to the identification of the suspects. We agree with that part of the court’s opinion and will now move forward with our cases,” Denver District Attorney Beth McCann said in a statement following the decision.

Bui told investigators he had been robbed the month before the fire. He then traced his iPhone to the home, according to court records. He admitted to setting the fire, only to find out the next day through news coverage that the victims were not the people who robbed him, according to police.

Bui’s arraignment is set for Feb. 1, according to court records.

The Associated Press contributed to this report.