VISTA (CNS) - Two gang members who participated in a retaliation shooting that killed two teenagers and left two others wounded in an Oceanside park were sentenced Friday to lengthy state prison terms.

Martin Melendrez, 25, who pleaded guilty to second-degree murder and attempted murder, was sentenced to 40 years to life behind bars.

Santo Diaz, 22, who was acquitted of first-degree murder then pleaded guilty to voluntary manslaughter, was sentenced to 39 years in prison.

The defendants were among four people charged in the March 13, 2013, shooting that killed 13-year-old Melanie Virgen and her 15-year-old friend, Edgar Sanchez at Libby Lake Park. The teenagers were innocent victims of a conflict between rival gangs, authorities said.

Michael Zurita, 22, pleaded guilty to assault with a semiautomatic weapon and was sentenced to 25 years in prison.

Kevin Brizuela, 20, was convicted of first-degree murder and has yet to be sentenced.

Oceanside police said the defendants fired on the victims about 9 p.m. near a makeshift memorial for two teens who had been killed in the park.

According to the prosecution, the victims were all sitting near each other on a couch that had been placed near the memorial when they were fired upon. The memorial was for Sandra Salgado, 14, and her boyfriend, 16-year-old Fernando Solano, who were gunned down in a gang assault two years earlier.