OAKLAND -- Hours after the father of a missing toddler was arrested Thursday morning on suspicion of child endangerment, search crews were focusing for the second time in two days on an Oakland shoreline.

Police have searched a handful of locations around Oakland, including the home where John Anthony Webb, 49, lived with his 21-month-old daughter, Daphne Viola Webb, and places they recently visited.

John Webb has not been named by police as a suspect in the girl's disappearance. However, police arrested him on the felony child endangerment charge after he told investigators that he had left the toddler in his car with his elderly mother, who suffers from dementia, immediately before she disappeared.

Daphne Viola Webb
Daphne Viola Webb (Oakland Police Department)

"We are concerned about the relationship with the child and the father," Oakland police Officer Johnna Watson said Thursday morning.

Webb was being held Thursday afternoon on $100,000 bail at Santa Rita Jail, according to Alameda County Sheriff's spokesman Sgt. J.D. Nelson.

Shortly before 2 p.m. Thursday, authorities began setting up crime scene tape and moving bystanders away from a parking lot area at the Martin Luther King Jr. Regional Shoreline, near Oakland International Airport. Members of the Alameda County Sheriff's Search and Rescue team and at least two search dogs were on the scene, with boats from the sheriff's office, the U.S. Coast Guard and Oakland police scanning the water close to the shore.

The Oakland police used sonar to scan the water, then checked any notable readings with an underwater camera. Visibility in the murky water was down to only about two feet, officials said.

The search began near one of the park's entrances at Swan Way and Doolittle Drive and headed northwest toward Alameda.

It was the second time in two days that police had searched the site. Police said Webb told them he spent a lot of time with his daughter at the park.

Investigators were also seeking witnesses who could verify seeing the girl with her father in the last 30 days.

Authorities handed out about 200 fliers with Daphne's picture and description Thursday in the neighborhood where she went missing. They plan to hand out more Friday.

Webb told police that just after 11 a.m. on Wednesday he left the child and his mother in the car and went into Gazzali's Supermarket at 79th Avenue and International Boulevard. He bought an energy drink and was in and out of the corner store quickly, according to a store clerk.

Webb told police he returned to his SUV and found his mother alone and Daphne missing from the back seat.

John Webb was arrested Thursday after he reported that his 21-month-old daughter was taken from his car near an East Oakland convenience store on Wednesday
John Webb was arrested Thursday after he reported that his 21-month-old daughter was taken from his car near an East Oakland convenience store on Wednesday morning. (Alameda County Sheriff's Department)

Police immediately interviewed Webb, his mother, Daphne's mother -- whose identity was not released -- and other relatives, said Watson. What the family members said and the state of the relationship between Daphne's mother and father was not known Thursday morning.

Watson said the child's mother is "not a person of interest" in the case. She said Webb, Daphne's mother and other relatives have remained cooperative with police in the investigation.

Police are working a two-pronged investigation, Watson said Thursday -- the initial missing person and kidnapping incident, and the subsequent child endangerment charge.

Police were also planning to retrace possible routes Webb took to the store from his home in the Oak Knoll area and were seeking video surveillance tapes and witnesses who may have seen something.

Police and the FBI also spent several hours at Webb's apartment on Greenridge Drive in Oakland, searching the home and talking to neighbors in an attempt to verify the father's story, police said. It was not immediately known what, if anything, was found at the home or what investigators learned.

On Thursday afternoon, yellow police tape remained up at the six-unit apartment building.

One neighbor said Thursday Webb had moved there about a year ago with the child and the child's mother, who had left several months ago. The neighbor could not remember the last time she saw the little girl.

Public records show that Webb, who lived in Sacramento for several years, was arrested in 2001 on a felony charge of discharging a firearm with gross negligence charge. He was later sentenced to two months in a sheriff's work project.

In 2002, he was arrested on misdemeanor charges of spousal battery and criminal threats. Those charges were dismissed the following year.

Webb has no criminal record in Alameda County.

Daphne's uncle, Josh Hayles of Vallejo, said he was contacted by police about his niece's disappearance on Wednesday then began seeing her face all over the Internet.

Hayles said Daphne's 30-year-old mother is his sister and called his niece a bubbly baby.

"She's a people person, she likes people," Hayles said. "Every time I see her she's a different person."

He said his family has been praying a lot since Daphne vanished and are working with police however they can.

"We've been letting them do their job," said Hayles. Webb and his sister had been together for years and that their relationship appeared amicable, he added, saying, "He's always been a cool person. Took care of his mother."

Daphne is described as black, about 2 feet tall and weighing about 30 pounds. She has short, black, curly hair, a medium complexion, brown eyes and is missing part of her left ear. She was last seen wearing an orange, two-piece pajama set with pink hearts and pink socks.

Police said they were evaluating a report from a resident several blocks away from the market that a girl with similar clothing was seen with an unidentified black or Hispanic woman between 30 and 40 years old who had long, straight black hair and was wearing a light-colored shirt and jeans.

Police and Crime Stoppers of Oakland are now offering up to $10,000 in reward money for information leading to finding the child. Anyone with information about the case or who has seen Daphne is asked to contact the Oakland Police Department Missing Persons Unit at 510-238-3352.

Staff writers Brittny Mejia, Matthias Gafni and Katie Nelson contributed to this report.