The Baker’s Dozen a cappella group is waiting to hear a decision from the San Francisco District Attorney’s Office on whether it will file criminal charges against the suspects who allegedly attacked members of the group at a party during its winter singing tour in California.

While leaving a New Year’s Eve party thrown in their honor, students in the all-male singing group were assaulted after two uninvited guests at the event had repeatedly insulted the students, witnesses said. As members of the Baker’s Dozen left the party, a dozen more assailants arrived at the party and the group proceeded to violently attack the Yale students. Members of the singing group sustained injuries that included a broken jaw, a concussion, a sprained ankle, black eyes and other bodily bruises.

The San Francisco Police Department has been widely criticized by media for mishandling the investigation into the attack. The police made no arrests at the crime scene, citing a lack of evidence, and many critics of their actions have said that the investigation has proceeded at an unsuitably slow pace. The SFPD has stated that the delay is part of an effort to handle a complicated situation with caution.

The a cappella group returned from their tour this weekend and are set to resume their normal performance schedule for the academic year, Baker’s Dozen business manager Zach Bucknoff ’08 said. All members of the group will perform regularly in concerts this semester with the exception of Sharyar Aziz Jr. ’10, who will have his jaw wired shut for eight weeks as a result of his injuries.

“It has been crazy, but we’re hanging in there,” Bucknoff said. “We’re all still recovering.”

Bucknoff said the group continued their planned winter tour after the incident, canceling only one concert to facilitate the SFPD investigation.

Several school officials, including University President Richard Levin, have made contact with the parents of the a cappella group members.

“It’s an appalling incident, and my only hope is that there is a thorough investigation,” Levin said.

Parents including Sharyar Aziz ’74, the father of Aziz Jr., have attributed the cause behind the slow-moving investigation to the fact that some of the suspects have been identified as the sons of a prominent local family.

Aziz Sr. said he has seen an increased effort by the police force to work the case this past week, which he thinks is mostly due to increased media coverage of the incident. He said he hopes to see District Attorney Kamala Harris file charges against the suspects soon.

“I want to make sure that these attackers are brought to justice and punished,” he said.

Aziz Sr. said it seemed unusual that the victims were not immediately interviewed at the scene of the crime and that the case was not assigned a supervising lieutenant until four days after the incident. His wife and son appeared on the Fox News show, “Hannity and Colmes,” last Thursday to speak publicly about the attack, and the hosts of the show are currently offering a $10,000 reward for any witnesses willing to come forward and testify.

“The group wants to be able to continue with their life at Yale and put this horrible event behind us,” Aziz Jr. said in an e-mail Monday afternoon.

In a response to recent criticism about the course of the investigation, SFPD Police Chief Heather Fong said to the San Francisco Chronicle that the suspects were released because witnesses could not tie the four individuals to the beating. Local residents, however, remain skeptical.

Attorney and former SFPD sergeant Leanna Dawydiak, whose home was the site of the party, said that Fong is either misinformed or “lying.”

“This is a simple situation, and there were lots of witnesses,” she said. “These are just attempts to cover it up.”

Dawydiak said the attack outside her home began after the Baker’s Dozen decided leave the party after two party guests had begun insulting the group. She said she thinks the two uninvited guests, whom she identified as Richard and James Aicardi of San Francisco, were angered by the attention the Yale students were receiving from the women at the party and proceeded to direct homophobic slurs at the students, calling them “homos,” “queers” and “fags” after seeing the a cappella singers lead the party attendees in a sing-a-long.

“It doesn’t matter if these guys are gay or not,” Dawydiak said. “If someone purposefully sought words to hurt you based on a characteristic you were born with, it can be termed a hate crime.”

The police are investigating whether underage drinking took place at the party and whether alcohol contributed to the crime, but Dawydiak said alcohol was not served in her home to her knowledge.

The SFPD flew down to the Los Angeles area last week to interview the Baker’s Dozen as they were finishing up their tour in California. Aziz Sr. said Lieutenant Leroy Lindo and the other SFPD officers in charge of the case initially suggested that the students fly back to San Francisco themselves under the assumption that the Yale students were wealthy enough to do so with ease.

“[Lindo] absolutely said that they should come to San Francisco because they are affluent,” he said.

But Lindo said the police department currently is doing everything in its power to determine what happened on the night of the party and has been working closely with the Baker’s Dozen and other witnesses in the past week.

“We work for the victim in the case, and we are making progress,” he told the News last week.

The Aziz family lawyer, Whitney Leigh, said although there has been no word from the San Francisco District Attorney’s Office, he hopes charges will be filed against the assailants within a few days.

The District Attorney’s Office could not be reached for comment Monday evening.

The Baker’s Dozen has released a statement on its Web site stating that the members of the group are “deeply disturbed” by the “violent and unprovoked attack” on them.