AUG. 16 — A California teenager who killed two classmates and wounded 13 others in a school shooting has tearfully apologized as he was jailed for 50 years.Charles Williams did not tell the court why he opened fire with his father’s handgun at Santana High School on March 5, 2001, but he said he felt “horrible about what happened. ”Judge Herbert Exarhos called the attack vicious* and fiendish*, but noted that Williams had endured* a difficult life at home and had no previous criminal convictions*.“If I could go back to that day, I would never have got out of bed,” the 16-year-old said, his voice breaking. He said the question of why Williams committed the attack remains unanswered.“In all likelihood, it is a question the defendant* will be struggling with daily to answer for himself,” Exarhos said.Prosecutors* had asked the judge to impose the maximum sentence of 425 years, saying Williams coolly* planned the assault* at the suburban San Diego school and shot classmates as they ran in terror.The teenager’s father has said his son, then 15, was the victim of frequent bullying* after moving to Santee from Twentynine Palms, a desert community east of Los Angeles.But Deputy District Attorney Kris Anton said the harassment* Williams said he suffered, such as having his skateboard stolen or being punched in the chin, did not justify the shooting.“The defendant is the bully. He took a gun to school and shot innocent kids,” Anton said during the sentencing hearing.In June, Williams pleaded* guilty to two counts of murder and 13 counts of attempted murder. The assault at the 2,000-student campus killed two boys, aged 14 and 17, and wounded 11 other students, a teacher and a campus monitor. (Difficulty: senior)