The first of three teenage gang members who admitted attacking a member of a rival gang with machetes in May, mutilating the victim's hands, was sentenced yesterday to 15 years in prison. Fairfax County prosecutors said Cristobal Z. Medrano, 18, had tattoos all over his body proclaiming his allegiance to Mara Salvatrucha, or MS-13, the dominant street gang in Northern Virginia. His attorney said Medrano and two fellow gang members were taunted and threatened by members of the South Side Locos gang and initially ran and hid, but then emerged with machetes and trapped one of the Locos members along Edsall Road in the Alexandria area.

The 16-year-old victim cornered by Medrano, Hayner R. Flores, 18, and Jose Cruz-Melendez, 19, was "trying to protect his head and face as the machetes were coming down on him," Assistant Commonwealth's Attorney Jay R. Nanavati said. During the attack, Medrano yelled, "MS represents!" as the blows rained down, Nanavati said.

Four fingers on one of the victim's hands and a thumb on the other hand were nearly severed but were reattached, and his head and back were deeply gashed. "They inflicted some really, for lack of a better word, medieval-type injuries on this person," Nanavati said.

Prosecutors asked for a 10-year sentence. But Circuit Court Judge Jane Marum Roush imposed the maximum sentence on both counts -- 20 years for malicious wounding and 10 years for gang participation -- then suspended half of each term and ordered that Medrano serve them consecutively.

After looking at the pictures of the victim's wounds, Roush said, "This is among the most serious cases I've ever had, short of murder."

Medrano was 17 when the attack occurred May 10. But because he had a long juvenile record and because the victim's injuries were so serious, prosecutors sought to try him as an adult. Medrano pleaded guilty in August in Fairfax Circuit Court to malicious wounding and participating in a street gang.

Flores, the first to be arrested, and Cruz-Melendez have pleaded guilty to the same charges and are awaiting sentencing.

Kris Eckerd, Medrano's juvenile parole officer, testified that Medrano was born to Salvadoran parents in New York and was sent to live with a grandmother in El Salvador when he was 3. Medrano bounced among different family members and witnessed many violent incidents while growing up there, Eckerd said.

Medrano returned to the United States in 1997, living first with his father and then moving several times, Eckerd said. He was arrested in 2000 for the first time, at age 14. Attempts to help him and his family with counseling, mentoring and other services were ineffective, Eckerd said.

Sometime after midnight May 10, Medrano, Flores and Cruz-Melendez were hanging out at a 7-Eleven on Edsall Road. "They were not armed; they were not looking for trouble," defense attorney Crystal A. Meleen said.

A car of young women pulled up and shouted chants for South Side Locos and insults to MS-13. Both gangs began in the Salvadoran community of Los Angeles and have now established formidable outposts in Northern Virginia, with MS-13 membership estimated at 2,000.

Nanavati said Medrano hurled a bottle at the car. Soon, a second car arrived, and three men with baseball bats chased Medrano, Flores and Cruz-Melendez, Meleen said. The three initially hid in bushes, then sprinted to an apartment, but their rivals remained outside, Meleen said. The three MS-13 members then emerged wielding machetes and chased down one of the SSL members.

The victim's family has paid $26,000 in medical expenses, Nanavati said, and the victim will require more surgery. The victim's mother wrote a letter to the judge saying, "I pray and hope that many young people and their families can learn from what has happened to my family . . . that they see what gangs can do to a person's life."

Medrano read a statement apologizing to the victim and his family. "I know that my part in this terrible incident was wrong," he said.