VALLEJO (KRON) — Vallejo Police are investigating a kidnapping of a 57-year-old woman for ransom.

Elvira Babb’s son John received a text message from an unknown number on June 30th threatening his mother’s life and demanding money if he did not cooperate or if he contacted the police.

Police report the text demanded less than $100,000 but wouldn’t specify the exact amount.

“At this point, we are worried, we are concerned about the victim and we’re hoping the public an help us locate her,” said Vallejo Police Department Lietenant Jeff Bassett.

Neighbors say Babb wasn’t financially secure herself and was looking for roommates at one point to help pay for rent.

“She was a sweet little thing, kept to herself pretty much,” said Babb’s neighbor Patricia Carr. “But when she came out, she was always smiling always bringing some food down cus she just had to cook for just one.”

Police say Elvira Babb was last seen on June 29th at the Sea Food City market in Vallejo after a co-worker dropped her off there.

Police have arrested 26-year-old Emmanuel Espinoza, 32-year-old Jalon Brown, 23-year-old Larry Young, and 27-year-old Lovely Rauzol in connection with the case.

One neighbor said off-camera they were surprised to hear the primary suspect, Espinoza, is allegedly involved saying he’s a nice guy.

All four suspects were booked into Solano County Jail Friday night on kidnapping for ransom charges.

John Babb went to his mother’s house that same day and could not find her. He found his mother’s dog dead inside the house.

“He was just barking really strange that day,” Carr said. “I don’t know what was going on or why. I didn’t see anybody.”

The FBI is helping the Vallejo Police investigate the case, as well as other nearby law enforcement agencies.

Authorities are still searching for Elvira Babb. Anyone with information about her whereabouts is asked to call the Vallejo Police Department at 707-648-4080.KRON4’s Ella Sogomonian also contributed to this article.