A 77-year-old grandmother who police say was brutally beaten in the head as she got off a Muni bus in San Francisco earlier this month passed away Friday morning.

Connie Ho confirmed the death of her grandmother, Lin Leong. Ho is hoping the public can help in finding the suspect.

"I beg for your help so we can find justice in my grandma's death and she doesn't die without knowing who caused it," Ho said.

Police said Leong was attacked on May 10. Investigators said the exact location of the attack is unclear -- possibly around Chinatown or Japantown.

"It really hurts that someone could do this to a random stranger," Ho said. "It's just not right."

Police believe a good Samaritan helped Leong just after her attack, moving her away from the side of the Muni bus and sitting her down on the sidewalk. But the person didn't stay at the scene and hasn't yet been interviewed by police, officials said.

Investigators are still trying to determine which bus Leong was exiting and at what time on May 10. The motive for the assault remains under investigation.

Anyone who witnessed the incident or has information about the suspect or the Good Samaritan, should also contact investigators and may do so via an email to San Francisco police Sgt. Trevor Kelly at Trevor.Kelly@sfgov.org, or via the Anonymous Tip Line at 415-575-4444 or Text-A-Tip to TIP411 and include "SFPD" at the beginning of the message.

NBC Bay Area's Terry McSweeney and Bay City News contributed to this report.