4th man held in fatal shooting of West Oakland mother

Chyemil Pierce was killed March 9, 2015, in Oakland. Police say she was caught in the crossfire of a gunbattle on Chestnut St. and was killed while trying to ensure her children got to safety. Chyemil Pierce was killed March 9, 2015, in Oakland. Police say she was caught in the crossfire of a gunbattle on Chestnut St. and was killed while trying to ensure her children got to safety. Photo: Family Photo Photo: Family Photo Image 1 of / 13 Caption Close 4th man held in fatal shooting of West Oakland mother 1 / 13 Back to Gallery

A fourth man was arrested and charged with the murder of a West Oakland mother who was caught in the cross fire of a gunbattle a half block from her home, Oakland police said Tuesday.

Michael Stills, 21, of Oakland was charged Monday in connection with the March 9 shootout on the 2800 block of Chestnut Street that killed 30-year-old Chyemil Pierce as she shouted for her children to run to safety.

Investigators said the shooting was the result of a confrontation between two groups north of where Pierce parked her car after picking up her 7-year-old son and 9-year-old daughter from school. She had been ushering her children to their nearby home when the gunfire broke out.

Stills was charged with murder and unlawful firearm activity. Three other men — Anthony Sims, 19, Shelton McDaniels, 29, and Jerry Harbin Jr., 29 — were arrested and charged with murder and a variety of firearm charges earlier this month.

Police said investigators continue to identify suspects in connection with this case.

Vivian Ho is a San Francisco Chronicle staff writer. E-mail: vho@sfchronicle.com Twitter: @VivianHo