Esteban Nuñez, the son of former state Assembly Speaker Fabian Nuñez, and his three friends have been accused of stabbing to death a Mesa College student, Luis Santos, 22, in an unprovoked attack in October.

Esteban, 19, and the three others - 22-year-old Ryan Jett, and 19-year-olds Leshanor Thomas and Rafael Garcia - all of whom live in the Sacramento area, returned to San Diego on Wednesday to face murder charges, a day after their arrests.

San Diego homicide Capt. Jim Collins said during a news conference at police headquarters that the four accused came to San Diego to visit friends, and to party near San Diego State University on October 3.

According to a search warrant affidavit filed in San Diego Superior Court, the four tried to get into a fraternity party but were turned away. About 2 a. m. on October 4, they confronted the frat boys - Santos and his friends. A verbal exchange between them escalated into a physical altercation and eventually into the stabbing. The defendants stabbed four men, killing Santos.

Paul Levikow, a spokesman for the San Diego County District Attorney's Office, said that each of the four accused is charged with murder, assault with a deadly weapon and vandalism. If convicted of murder, they face a maximum sentence of life in prison.

Estaban's father, Fabian Nunez - who stepped down as Assembly speaker this year because of term limits - released a statement saying he had faith in the justice system. He said: "This is a very difficult and painful experience for every family involved. Maria and I love our children very much. We are confident our son Esteban will be cleared of the charges he is facing."