DES MOINES, Iowa (AP) — Five teenagers charged with fatally shooting a 15-year-old boy and seriously wounding two teenage girls outside a downtown Des Moines high school last month pleaded not guilty in court filings.

Manuel Buezo, Henry Valladares Amaya, Romeo Perdomo, Octavio Lopez Sanchez Jr., all 17; and Daniel Hernandez, 18 , were to appear in court on Friday, but their hearings were called off when their attorneys filed documents indicating their desire to enter a written arraignment and plea of not guilty. The filings avoided personal appearances before a judge at a courtroom inside the Polk County Jail.

They have all been charged as adults with murder and attempted murder. A judge set their trial dates for June 27.

They are among 10 teenagers who were arrested after Jose Lopez was killed March 7 in what prosecutors call a hail of gunfire from the occupants of three cars. His sister and her female friend were seriously injured.

Arraignment hearings for three others charged as adults — Kevin Isidro Martinez, 16; Braulio Hernandez-Salas, 17 and Gumaro Marquez-Jacobo, 18 — were delayed at the request of prosecutors, court filings show. A judge set new arraignment dates for May 13.

The status of cases for two others similarly charged but who remain in juvenile court is not known since those proceedings are not posted publicly.

Police investigators concluded that the shooting was the result of a dispute between rival gang members, court document indicated. Police have video evidence of the teens getting into three vehicles and driving by the school spraying 42 bullets from six guns. Only three of the guns have been recovered, court documents indicated.