Colorado school attacked and prevented from Columbine rehearsal

A few months before a deadly shootout in Colorado this week, a parent warned that student violence and harassment could cause "a repeat of Columbine".

The parent also alleged "a very strong drug culture" on the suburban campus of Denver, warning that it was "the perfect storm".

The call was spent five months before the attack.

One student died and eight others were injured Tuesday in a shootout at STEM School Highlands Ranch.

The anonymous parent called a school district official, who detailed the allegations in a letter to the school principal.

According to CBS News, the parent mentioned the 1999 shooting at Columbine High School, one of the most notorious attacks in the United States, which killed 13 people just 8 km away from Tuesday's assault.

But the school director reportedly said that a subsequent investigation would have found no evidence to support the allegations.

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STEM school officials filed a lawsuit against the anonymous parent in January for broadcasting "defamatory statements" about the school, reports CBS News.

The BBC contacted the school for comment but did not receive an immediate response.

Penelope Eucker, school principal, said in a statement to CNN, "The safety and well-being of our students and staff is our highest priority.

"Like any school with more than 1,800 students, we receive complaints that we all take seriously and conduct a quick inquiry."

Kendrick Castillo, eighteen, died in the assault while he was trying to disarm one of the assailants, according to his comrades.

The two suspects involved in the shootings, aged 18 and 16, were charter school students. Their motivation is not clear.

They must appear in court next week.