PORTERVILLE, Calif. >> An alleged gang member pleaded not guilty Tuesday to killing six people, including a teen mother and her baby, last month at a central California home associated with a rival gang, prosecutors said.

The Jan. 16 massacre shocked rural Goshen, a community of about 3,000 people in the agricultural San Joaquin Valley.

Noah David Beard, 25, was arraigned Tuesday and is being held without bail, according to the Tulare County District Attorney’s Office. Authorities say he shot Alissa Parraz, 16, and her 10-month-old baby, Nycholas Parraz, in the back of their heads.

Beard is scheduled to return to court Feb. 16. The Tulare County Public Defender’s Office, which is representing him, did not immediately respond to a request for comment.

Beard’s alleged accomplice, 35-year-old Angel “Nanu” Uriarte, remains hospitalized in custody after he was wounded in the shootout with federal agents last week. His arraignment has not been scheduled.

Both are charged with six counts of murder and other crimes. They each face a potential sentence of the death penalty or life in prison without parole.

Investigators believe the two suspects have ties to the Nuestra Familia prison gang. Uriarte was convicted in 2015 of assault with a firearm in association with a street gang, and Beard had juvenile convictions, prosecutors said in a court filing.

The suspects and members of the victims’ family have a long history of gang violence but the motive for the shooting “is not exactly clear,” Boudreaux said at a news conference last week.

The other victims were identified as: Rosa Parraz, 72; Eladio Parraz, Jr., 52; Jennifer Analla, 49; and Marcos Parraz, 19.

The Goshen killings were part of a violent and deadly month in California.

On Jan. 21, a gunman killed 11 people and wounded nine others at a Monterey Park dance hall before later killing himself. And on Jan. 23, authorities said a farmworker killed seven people in back-to-back shootings at two Northern California mushroom farms.