The teen arrested and accused of stabbing a former classmate to death in Longmont over the weekend had a 'death list,' according to the district attorney prosecuting the case.

9Wants to Know confirmed former Green Mountain High School student Makayla Grote was stabbed to death by a 15-year-old Saturday in Longmont.

In juvenile court Monday, Boulder County prosecutors said a 'death list' was found in the teen's room and Makayla Grote's sister was the first name on that list.

The teen had been seen lurking around her home earlier in the day, around 11:00 a.m., prosecutors say, before returning and knocking on Makayla's door Saturday evening.

The sister was in the shower when the teen suspect knocked, which is why Makayla answered the door, prosecutors say.

When she answered the door, the DA says she was stabbed once in the head and once in the chest with what he described as a 'hunting knife.'

Makayla was found suffering from stab wounds in the 2400 block of Airport Road at 6:00 p.m. Saturday evening, according to Longmont Police. Although she was rushed to the hospital, she died from her injuries.

Hours later, Longmont Police took the 15-year-old into custody on first-degree murder charges connected to Makayla's death.

The District Attorney's office also mentioned the suspect and Makayla's sister had sent 'troubling text messages' to each other about the so-called 'death list.'

Makayla graduated from Green Mountain High School last year. The suspect in her death was also a former student at Green Mountain, according to the school's principal, Colleen Owens.

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Inside the suspect's home, police found Molotov cocktails prosecutors said in court Monday afternoon.

In court on Monday, the DA also said the day before Makayla was stabbed to death, the teen assaulted his grandfather and threatened his mother with a knife.

Bond for the 15-year-old has not been set. He remains in custody in Boulder County's juvenile detention facility.

His next court appearance is Wednesday morning for a formal filing of charges.