SAN DIEGO - A massive search continued Friday for a man suspected of abducting a 16-year-old family friend as police warned he may have abandoned his car while on the run and rigged it with explosives.
James Lee DiMaggio, 40, may have had an "unusual infatuation" with the missing girl, Hannah Anderson, an official said.
The grandparents of Hannah Anderson made an emotional plea Friday for her safe return.
"We need her home, she needs to be home," her grandmother, Sara Britt, said.
The two are hoping for the best, but preparing for the worst as the Amber Alert issued for grandkids Hannah and Ethan Anderson entered its fifth day.
The alleged kidnapper is suspected of murdering Hannah's mother Christina Anderson and possibly Ethan. The L.A. Times reported that Christina Anderson died of blunt force trauma to the head.
"We've lost our life, my only daughter, my only child," Britt said.
The grandparents said they are hoping for the best and has a message for DiMaggio.
"You've taken our heart and soul, you've taken my only child ... please let Hannah go," she said.
A vigil will be held Friday at Lindo Lake in Lakeside at 6:30 p.m.
Authorities on Thursday warned the public to consider DiMaggio highly dangerous and likely armed, potentially with explosive or incendiary devices that he might use to booby-trap his vehicle or any structure in which he may hide out.
Sheriff's Lt. Glenn Giannantonio would not reveal why authorities believed that the suspect might have bomb-making capability and intentions, and said only that they reached that conclusion "based on evidence uncovered thus far in our investigation."
Law enforcement officials believe DiMaggio may be driving his blue 2013 Nissan Versa sedan, California license 6WCU986, and might have headed to Texas or Canada, though they conceded that he could have reached almost any destination since disappearing over the weekend.
"As we've said all along, he could be in Mexico, he could be in Canada, or he could be a mile away," sheriff's spokeswoman Jan Caldwell said. She said the suspect was an avid camper and may be trying to avoid capture by traveling through or seeking shelter in wilderness areas.
Amber alerts have been issued in California, Oregon, Nevada and Washington, according to the National Center for Missing and Exploited Children.
DiMaggio allegedly killed longtime friend Christina Anderson, 44, and an unidentified child, possibly her son. The victims' burned bodies and the remains of a dog were found Sunday evening in the rubble of the suspect's home on Ross Avenue, which investigators believe DiMaggio burned down along with its detached garage before fleeing.
Authorities were awaiting the results of DNA comparisons to determine if the deceased child was Ethan. Those tests could take several more days to complete, or might wind up inconclusive, although an autopsy determined that the smaller set of remains was consistent with an 8-year-old boy, Giannantonio said, and authorities were aware of no other local missing children of that age.
About a half-dozen FBI special agents have joined the investigation as a means of expanding "interstate and international capabilities," according to Caldwell.
The suspect's sister told 10News her brother was a man of exemplary character, and someone else must have committed the crimes and abducted or killed him in the process.
"He helped everyone that he knew in every way that he could, and he was a kind, kind, giving, loving person," Lora DiMaggio said. "He's done so much for so many people, and I just want him to come home."
In addition to having been a good friend to Brett and Christina Anderson for about 20 years, the suspect, who worked as a computer technician, was close to their children for their entire lives, investigators said.
Officials urged anyone spotting DiMaggio -- who is about 5 feet 9 inches and 150 pounds, with brown hair and brown eyes -- to avoid approaching or contacting him, and to instead contact law enforcement immediately.
Hannah is about 5 feet 7 and 115 pounds, with blond hair, blue eyes, a navel ring, a nose stud and pierced ears. Ethan was described as about 4 feet 11 inches and 65 pounds, with sandy blond hair. All three are white.
Anyone with information on the possible whereabouts of the suspect or the missing children was asked to call the San Diego County Sheriff's Department at (858) 565-5200.