SAN DIEGO -- The son of former Assembly Speaker Fabian Nunez and three other young men accused of killing a 22-year-old college student near San Diego State University pleaded not guilty Thursday to murder and other charges.

Esteban Nunez, Rafael Garcia and Leshanor Thomas, all 19 years old, and 22-year-old Ryan Kelly Jett are accused in the fatal stabbing of Mesa College student Luis Santos, who was attacked sometime after 2 a.m. on Oct. 4.

In addition to murder, the Sacramento residents face three counts of assault with a deadly and a single count of misdemeanor vandalism.

Prosecutors have not filed gang allegations, but tried Thursday afternoon to make the case that the defendants are at least gang wannabes.

Deputy District Attorney Jill DiCarlo told Judge David Szumowski that they all have biohazard-type tattoos and call themselves "The Hazard Crew" or "THC," the initials for the active ingredient in marijuana.

"They want to be gang members," the prosecutor said.

Three of the defendants traveled from Sacramento to San Diego on Oct. 3, where they met up with Thomas to party, DiCarlo said.

They became angry when they were denied entry to a fraternity party and bragged to Garcia's cousin that they all had knives and wanted to steal a computer or fight someone, the prosecutor alleged.

As they went out, the defendants punctured the tires of a trailer using their knives, DiCarlo said.

At the same time, five people in the victim's group -- none of them were armed -- were coming from a different party and got into a fight with the defendants, the prosecutor said.

DiCarlo alleged that the defendants challenged the victims and Santos and a friend tried to run away, but were attacked anyway as the groups got back together.

Santos was stabbed in the heart and bled to death. Another man was stabbed in the back and stomach, and a third was stabbed in the shoulder. A fourth person was punched in the eye and had to undergo plastic surgery, according to DiCarlo, who said a fifth person escaped injury.

After the fight, the defendants went back to Sacramento and burned some clothes in the Sacramento River and also threw their knives into the river, DiCarlo alleged.

Outside court, Fabian Nunez stood silently with his son's mother and sister while Esteban Nunez's attorney, Brad Patton, told reporters that his client is not a gang member.

The attorney said he had been aware of the investigation for two months and offered to cooperate with authorities. Instead, investigators went to Sacramento on Tuesday, arrested the defendants and brought them back to San Diego, Patton told reporters.

"They chose to turn this into a bit of a spectacle," he said.

Patton claimed the defendants acted in self-defense and were not the only ones who had weapons during the altercation.

The attorney said one of the defendants -- Jett -- was stabbed during the fight.

"These young men are not guilty of the offenses which they are charged, and that will bear out in court," he said.

Speaking for the Nunez family, the attorney asking the media to respect their privacy. He said the family was under a "huge" amount of emotional stress.

"They believe 100 percent in their son's innocence. They stand behind it," Patton told reporters.

Paul Pfingst, who represents Garcia, said his client was a college student with no prior criminal record. Pfingst called leaks in the case "shameful."

"This case has been handled by way of leaks that have been targeted, that have been hysterical, that have been inaccurate and have been intended to prejudice the rights of these young men," the attorney said.

Pfingst questioned why it took 60 days to arrest the defendants if the case was as straightforward as prosecutors said.

The three 19-year-olds are being held on $2 million bail, while Jett is being held without bail because he allegedly violated probation on another case.

Jett has a prior felony conviction for illegal possession of ammunition and a misdemeanor conviction for DUI, according to prosecutors and court records. Bail was also set at $2 million for Jett on the murder case.