A statewide Amber Alert remained in effect Wednesday morning for two San Diego children authorities say may have been abducted by a neighbor who allegedly killed their mother.
Authorities believe that James Lee DiMaggio, 40, may be en route to Canada or Texas since the body of his neighbor, Christina Anderson, 44, was found in a burned-down home and her children missing.
No one has seen 16-year-old Hannah Anderson or her 8-year-old brother, Ethan, since their mother's body was discovered and DiMaggio disappeared over the weekend.
The remains of a child were also found in what was left of the home, but the child's identity and cause of death have not been determined, said Lt. Glenn Giannantonio of the San Diego County Sheriff's Department's homicide detail.
It is believed that DiMaggio has one or both of Anderson's children with him in his blue Nissan Versa, California license plate 6WCU986, Giannantonio said.
Giannantonio said investigators are chasing numerous tips but "realistically we don't know where they're going."
On Monday, authorities issued an Amber Alert -- first for San Diego County, then statewide.
It was the first time the state has used a new national Amber Alert system administered by the Federal Emergency Management Agency. Rather than being sent as text messages, the alerts were transmitted on an exclusive frequency that can reach tens of thousands of people at the same time -- even if those people are crowded into one place, such as a stadium, and even, as some users discovered this week, if a cellphone is set to silent.
"It's a needle in a haystack," said Bob Hoever, who runs the Amber Alert program for the National Center for Missing & Exploited Children. "But the more eyes and ears we have, the smaller the haystack becomes and more likely we'll rescue a child."
Outside of the San Diego County Sheriff's Department Tuesday, the children's father addressed DiMaggio.
"Jim," Brett Anderson said: "I can't fathom what you were thinking. ... Let my daughter go, you've taken everything else."
Although Anderson only mentioned his daughter, investigators from the Sheriff's Department say it is possible that DiMaggio also has Ethan.
Anderson urged Hannah to run away if she gets a chance.
Giannantonio said the medical examiner was attempting to determine if the unidentified body found in the burned-down home was one of the Andersons' children, possibly Ethan. The children thought of DiMaggio as "Uncle Jim," he said.
The Andersons were only known to have two children, he said.
DiMaggio is the owner of the home in Boulevard and had a "close platonic relationship" with Christina Anderson, authorities said.
Anyone with information on the case is asked to call the San Diego County Sheriff's Department homicide detail at (858) 974-2321 or (858) 565-5200, or San Diego County Crime Stoppers at (888) 580-8477.
A neighbor, Tom Calgaro, said that DiMaggio was "soft-spoken, very polite, easy-going. We used to chat over the fence."
He noted that DiMaggio was particularly friendly with Hannah, taking her to Hollywood to celebrate her 16th birthday.