SAN JOSE -- The murder trial against a gang who set upon a teenage partygoer in a shockingly violent attack dragged on for six months, making it one of the lengthiest in county history. But the jury delivered its verdict Tuesday in record time.

After deliberating just 3 1/2 days, the Santa Clara County panel convicted all seven gang members of murder in the vicious 2007 stabbing death of Adrian Medina, who didn't belong to any gang.

The actual killers -- David Ayala, who stabbed Medina 25 times, eviscerating him and piercing his heart, and Carlos Valdez, who fractured his skull with a baseball bat -- were found guilty of first-degree murder. Ayala was only 16 years old when he straddled Medina, 19, and repeatedly knifed the teen. Valdez was 17.

The jury also found five other gang members guilty of second-degree murder. The other defendants participated in the attack in a variety of ways, including beating up three of Medina's friends who tried to intervene and thus are equally culpable under the law on the murder charge.

All seven young men are members of Los Latinos Locos gang, or Triple L. Dressed in button-down shirts and sweaters Tuesday, they looked more like choir boys than hoodlums -- except for one young man with a white jagged scar from a fight on his shaved scalp.

Nine uniformed deputies kept a close watch over the courtroom packed with the young men sitting at three long tables inside the well, and their tense relatives in the audience.

As the verdicts were read, the defendant who played the most limited role in the attack, David Estrada, was the only one to break into tears, though he shoved away a box of tissues a deputy had brought over.

Some of the women in the audience gasped and sobbed, but the response was muffled because Judge David A. Cena had threatened to expel anyone who made a disturbance. District Attorney Jeff Rosen also was in the courtroom to hear the outcome of what had been an extremely difficult case, for both political and logistical reasons.

Helped police

Prosecutor David Pandori said the case was a challenge because it was dark when the group jumped Medina, and the attack lasted only minutes. But San Jose police, he said, never gave up.

He also praised the jury of three women and nine men for delivering an unambiguous message.

"This was clearly a gang attack by multiple gang members on an individual who was in the wrong place at the wrong time,'' Pandori said. "The issue becomes, 'Are you going to hold all the individuals responsible for a group attack?'

"This jury has said, yes, if you are involved in a gang attack, you are going to be held accountable.''

All seven killers face potential life sentences: a maximum of life without possibility of parole or 38 years to life for first-degree murder, and at least 15 years to life for second-degree murder. Gang enhancements for all seven, and various assault charges for the other six adds up to decades before any are released — if ever.

The gang had been counting on fear of retaliation to shield them, the prosecutor said. But several people, including three girls who were at the scene -- one of whom is related to one of the defendants -- were so horrified by the crime they wound up helping police.

Two other gang members involved in the attack also testified against the men.

No reason

The murder occurred when members of the gang crashed a party in East San Jose. Medina was returning to the party on Brigadoon Way after retrieving some alcohol from his car. At that point, said Pandori, the Los Latinos Locos gang members jumped him for no reason.

As Medina was dying, he told a friend who came to his aid that "Everything is going to be OK" and then choked on his blood, Pandori said in his closing arguments.

The case cost county taxpayers about $2 million in legal fees for the indigent defendants.

The trial was delayed until about six months ago for several reasons, including two attorneys falling ill and a third who moved to have his client declared incompetent to stand trial. The longest delay came after a judge concluded that the previous prosecutor improperly concealed crucial evidence from defense attorneys in 2011 on the eve of trial, including the knife police recovered from a sewer.

To salvage the case, Rosen yanked prosecutor Daniel Carr off the matter, eventually suspending him for a month without pay, and the case was reassigned to Pandori.

Contact Tracey Kaplan at 408-278-3482. Twitter.com/tkaplanreport.