SAN DIEGO -- A former South Bay high school mariachi music teacher who had sexual intercourse with a 17-year-old female student was sentenced Tuesday to a year in custody, which he will be allowed to serve in a work furlough program, and five years probation.

Carlos Hernandez, 28, pleaded guilty Feb. 6 to two felony counts of having illegal sex with a minor more than three years younger than him, one felony count each of oral copulation on a person under 18 and sexual penetration by a foreign object, and a misdemeanor charge of furnishing alcohol to a minor.

As a result of the plea bargain, 28 sexual assault charges were dismissed.

Judge David Danielsen also sentenced Hernandez to three years in state prison, but suspended that term as long as the defendant successfully completes probation.

Hernandez, who must also register as a sex offender for life, could have faced up to 5 1/2 years in state prison.

In sentencing the defendant, Danielsen also considered the fact that Hernandez had a sexual relationship with two other 17-year-old girls, said prosecutor Rachel Cano.

Defense attorney Robert Boyce told the judge that his client admitted to having unlawful sex with only one of the three.

Boyce said one of the alleged victims was not a student at the school where Hernandez taught.

"He certainly stepped over the boundaries," the attorney said of his client. "He's lost what he worked for from a young age in life. He did make a positive impact on a lot of people."

Boyce said Hernandez is in therapy and working in a different field.

The prosecutor said Hernandez "groomed" and "seduced" the girls he taught by befriending them, then calling them on the phone excessively.

"They idolized him," Cano told the judge. "He took advantage of those girls."

Cano said Hernandez made the girls videotape themselves masturbating and turn the tape over to him.

The now 20-year-old victim testified at a preliminary hearing last November that Hernandez repeatedly had sex with her in a Sweetwater High School locker room, in her home and in his car.

The victim said she went to police last year after learning that Hernandez had been arrested on suspicion of molesting another student.

Two other women testified they had similar sexual experiences with the defendant when they were students.

On Tuesday, through a victim advocate, the victim told the judge she was "confused and overwhelmed" and withdrew from school once she got up the courage to expose the defendant.

She urged the judge to send Hernandez to prison.

The defendant apologized before he was sentenced.

"I'm truly sorry," Hernandez said, looking out at the victim. "It was never my intention for you to feel that way."