(CNN) -- The 911 call is accusatory. The woman flatly tells the dispatcher she just witnessed several police officers in East Bakersfield, California, beat a man to death.
The woman -- identified by the local newspaper as Salina Quair, 34 -- happened upon the scene as she left Kern Medical Center, where the father of four would later die.
"There's a man laying on the floor, and your police officers beat the sh-t out of him and killed him," said Quair, according to a tape of the 911 call obtained by CNN affiliate KERO-TV.
"I'm right here on the corner of Flower and Palm right now and you have one, two, three, four, five, six, seven, eight sheriffs. The guy was laying on the floor, and eight sheriffs ran up and started beating him up with sticks. The man is dead laying right here, right now," she continues.
The sheriff's office has named the seven deputies involved in the incident, including a sergeant, while the California Highway Patrol has yet to name its two officers who responded to the scene.
The area is largely residential, packed with one-story homes and small apartment complexes. In addition to the hospital, East Bakersfield High School and the county coroner's office are within two blocks of the intersection where David Sal Silva died.
The Kern County Sheriff's Office has said it will not comment until the investigation is complete, but a news release says the incident began May 7 just before midnight.
A deputy responded to a call that a man, later identified as Silva, 33, was lying on the ground, possibly intoxicated.
Silva was "uncooperative," according to the sheriff's office, even after a canine was deployed.
"The suspect continued to actively resist the deputy and the K-9. Additional deputies arrived on scene, along with two CHP officers who responded to assist. The suspect continued to resist and received baton strikes from the deputies attempting to take him into custody," according to the sheriff's news release.
After Silva was restrained, police requested medical assistance for his injuries, the release said. He was having trouble breathing and was taken across the street to the hospital.
"While being treated at KMC, the suspect was pronounced dead at about 12:44 a.m.," the news release said.
Several witnesses have painted a more brutal picture, saying that Silva was crying for help and officers continued to beat him until he fell silent. Others have said they captured the incident on their cell phones. Two of those witnesses hired attorneys after police confiscated their phones, KERO reported.
In a news release Tuesday, the Kern County Sheriff's Office said that Youngblood has requested the FBI's help in analyzing "two cell phones pursuant to a search warrant related to the ... death of David Silva." It was not immediately clear which phones these are or what "forensic analysis" is being done, though the office did say that Bakersfield police saw one of the phones on video from the incident, but not the other one.
Youngblood also asked the FBI to conduct a "parallel" investigation into the incident.
"I think it's the right thing for the public, and I think it's the right thing for this organization," the sheriff told reporters Tuesday.
The only video released thus far is from a security camera, and the quality is poor. It appears to show two men scuffling for about two minutes before another man arrives. The two men appear to repeatedly hit the third man as he's on his knees and later lying on the ground.
Police cars arrive and officers gather around the man on the ground, but their actions aren't clear. The video is grainy, and the blur of light and shadows makes it difficult to determine what is happening.
Witnesses told CNN they were awakened by the incident. One witness, who asked not to be identified, described a chaotic scene.
"He was asking for help. He was screaming with pain. He only got to ask for help like three times," he said. "Those hits were brutal."
Sheriff Donnie Youngblood promised a fair investigation into the incident.
"I'm waiting till this investigation is done so I can look at it objectively and decide whether we did something wrong, and If we did, I'll stand up and tell you that we did. If we didn't, I'll stand up and tell you that we didn't," he told KERO.
In November, the family of Jose Lucero, 33, won a $4.5 million civil judgment against the Kern County Sheriff's Office, according to The Bakersfield Californian. After the mentally ill Lucero had made delusional 911 calls, four deputies beat, pepper-sprayed and Tasered him, killing him in front of his parents, according to the newspaper's report about the 2010 incident.
CNN's Eliott C. McLaughlin and Stephanie Elam contributed to this report.