(Des Moines, IA) -- Des Moines police are announcing they have made four more arrests related to the shooting outside East High School earlier in March. The update from police late Tuesday evening says the four teens between the ages of 16 and 18 are each charged with one count of first-degree murder and two counts of attempted murder. These are the same charges the initial six teenagers arrested are facing. The Des Moines Police Department is saying residential security cameras were able to see the teens in three cars firing shots at the victims. Police say a total of 42 bullet shells were found combined from the scene and the suspects cars. 15-year-old Jose David Lopez was killed and two female East High students were injured in the drive-by shooting.