On Tuesday afternoon, a school shooting in Highlands Ranch, Colorado, left one student dead and eight others injured, authorities said. /VCG Photo

Two suspects – one adult and one juvenile – are in custody after the shooting. /VCG Photo

The adult suspect was later identified by the sheriff's office as 18-year-old Devon Erickson, described by a next-door neighbor as "a quiet young man who sometimes deflected eye contact and played several musical instruments," according to the New York Times. /VCG Photo

The shooting started just before 2 p.m. The suspects "walked into the school, got deep inside the school and engaged students in two separate locations," a local sheriff said. /VCG Photo

Authorities have confirmed that there are no other suspects. Their motives remain unknown so far, waiting for further investigations. /VCG Photo

The shooting is only weeks removed from the 20th anniversary of the Columbine High School shooting, about seven miles away from STEM School Highlands Ranch, and thus rattled the area even more. As the White House said in a statement, "This community and those surrounding it know all too well these hateful and horrible acts of violence." /VCG Photo