Three children and a 21-year-old were killed in the hail of gunfire as a 2-year-old`s birthday cake was about to be cut Nov. 29 in Stockton.

A vigil Nov. 30 in Stockton, Calif., for the young victims of a shooting at a family birthday party.Benjamin Fanjoy / Getty Images

Shooters, clad in all black, fired more than 50 rounds from at least five weapons during a deadly mass shooting at a child`s birthday party in Northern California last month, authorities said Tuesday.

Even though investigators have leads on this case out of Stockton, San Joaquin Sheriff Patrick Withrow said it could still take months before arrests are made.

"I`m asking the public to be patient. I know this is going to be difficult, but this is not going to be in a week or two," he told reporters.

"This is going to take months to process all this, figure out who did this."

Withrow said the shooters had nearly all of their faces covered during the attack.

"You`ve been asking me for descriptions on the people that did this?" he said. "Well, the only information we`re getting so far from the folks who were at the scene was that the people involved in this were dressed all in black and had face coverings, so all you could see was this," he said, gesturing toward his eyes.

Four people were killed and 11 others wounded when the gunfire erupted at the party in Stockton on Nov. 29, authorities said.

A 2-year-old`s birthday cake was about to be cut when the shots rang out, officials said. Three of the fatally wounded were children.

"At least 50 rounds" were fired, Withrow said.

"We`ve been able to determine that there were at least five different firearms that were fired at this birthday party, (a) birthday party that killed three innocent children and a young adult."

Withrow did not say how many shooters authorities are looking for but hinted that investigators have some idea who the shooters could be.

"But that (the limited description) doesn`t mean we don`t know who they are or don`t believe we know who they are," Withrow said. "We just need to follow the evidence to prove who was there (and) who did this heinous act and that`s going to take a lot of time."

Victims Journey Rose Reotutar Guerrero, 8, and Maya Lupian, 8, were identified by their schools.

Amari Peterson, 14, was also fatally wounded during the attack, Stockton city officials said. The fourth victim, Susano Archuleta, 21, was identified by his family.

The deadly attack unfolded at a banquet hall on the 1900 block of Lucile Avenue in Stockton, officials said.

Stockton is the county seat of San Joaquin County, which grows more than half the state`s farm products. The city, with a population of about 320,000, is roughly 50 miles south of Sacramento and 80 miles east of San Francisco.