In the March 7 shooting death of a teenager outside a Des Moines high school, police charged four more teens with murder on Tuesday.

Six other people were earlier arrested in the death of Jose David Lopez, 15, and the shooting of two teenage girls. The girls survived the shooting that took place along the edge of the East High School campus, near downtown Des Moines, reported ABC News.

The additional suspects were charged with two counts of attempted murder and first-degree murder, just like those who were arrested earlier. Gumaro Marquez-Jacobo, 18; Kevin Isidro Martinez, 16, Braulio Hernandez-Salas and Daniel Hernandez, both 17, were the additional people arrested. Police said that the latest arrests were made by investigators after they reviewed surveillance videos and interviewed suspects and their acquaintances.

The probe showed six guns were used in the shooting. Cops recovered 42 shell casings from the suspects' vehicles and the shooting scene.

Des Moines police said earlier this month that authorities had arrested six teenagers, including a 14-year-old, according to NPR. Gunshots fired outside the school came from multiple shooters from different vehicles, police said at the time. The 15-year-old killed, who was not a student at the school, was the intended target of the shooting, said cops. The two girls, aged 16 and 18, who were also shot attend East High School. Police said that they were simply bystanders caught in the drive-by shooting.

The incident was described by Principal Jill Versteeg as "everyone's worst nightmare," and urged parents to "hug your students and love them."

School shootings have "become too common," according to Superintendent Thomas Ahart, who said that "real change to gun laws and access would go a long way to help us." He added that their staff and students are "forced to train for these incidents and the trauma associated with the repeated drills and incidents will remain with them for years to come."

Following the shooting, dozens gathered in the school's gym to remember Lopez, Des Moines Register reported. Reflecting on Lopez's death, school officials, parents, religious leaders and politicians sat quietly. Councilperson Connie Boesen said that as a community, they "have to come together and we all need to help support the youth and make sure that they have good and positive experiences."

Representation image. Pixabay.