OAKLAND -- A 17-year-old Oakland girl admitted Tuesday that she is guilty of assault with a deadly weapon for brutally stabbing a 75-year-old Berkeley woman near the Berkeley Rose Garden on March 16.

The girl is scheduled to return to Alameda County Juvenile Court on Sept. 20 to be sentenced.

Alameda County Assistant District Attorney Walter Jackson said the 17-year-old could be sent to the California Youth Authority for up to seven years or she could be placed in a mental health facility, as she has suffered from mental problems for much of her life.

In an incident that shocked North Berkeley residents, the girl allegedly grabbed a 75-year-old woman walking with her husband in the 1200 block of Euclid Avenue in Berkeley about 6:30 p.m. on March 16 and slashed the woman's throat from behind with a kitchen knife.

The suspect, who was 16 at the time, was arrested the next day and the elderly woman was able to recover from her wounds.

Several weeks later, Hamaseh Kianfar, 30, an Alameda County Juvenile Hall guidance counselor, was charged with being an accessory to attempted murder for allegedly being with the suspect at the time of the attack, driving her from the scene and failing to report the incident to police.

Kianfar, who resigned from her job shortly after she was charged, is scheduled to return to Alameda County Superior Court on Sept. 15 for a pretrial hearing.

The juvenile originally was charged with both attempted murder and assault with a deadly weapon so prosecutors could keep their options open and pursue alternative legal theories.

Jackson said that after reviewing the circumstances of the case, including the girl's mental problems, he decided that an assault with a deadly weapon charge alone would be more appropriate.

He also said it would be difficult to prove that the juvenile had a specific intent to kill the 75-year-old woman.

Since the juvenile court system uses different terms and procedures than adult court, juveniles don't plead guilty. The juvenile court equivalent of a guilty plea is an admission that a crime was committed.

At a hearing on Aug. 19, Juvenile Court Commissioner Mark Kliszewski ordered the girl to receive two weeks of intensive treatment after a doctor said the girl's mental state had deteriorated.

But Jackson said that after the girl was treated and given medication, her attorney, Deputy Public Defender Cliff Blakely, decided that her mental state was good enough so that she was sufficiently capable of understanding the charges against her and admitting legal responsibility for her crime.

Blakely wasn't available for comment today.

Jackson said the 17-year-old "never denied the offense."

He said he won't decide until the Sept. 20 hearing whether to recommend that the girl be sent to the CYA or if a mental health facility would be more appropriate.

But he said that if the girl is sent to a mental health facility, it must be a locked facility because the girl has "an extensive and well-known history" in the juvenile justice system.

"I've been in court with her before," Jackson said, although he declined to disclose the details of the juvenile's criminal record.

The veteran prosecutor said, "She has to be in a locked facility. The question is: what and where and for how long."