A family of four has vanished without a trace from its serene San Diego neighborhood, prompting an investigation by police who so far say they have no tips as to what may have happened.
Joseph McStay, 40, and his wife, Summer, 43, have been missing for more than two weeks with their two young children, Gianna, 4, and Joseph, 3.
According to Lt. Dennis Brugos of the San Diego Sheriff's Office, authorities located the McStay family's car, a white 1996 Isuzu Trooper, with the kids' car seats still intact, two blocks from the U.S.-Mexican border, and 80 miles from the family's Bonsall, Calif., home, prompting questions about any possible ties the family may have had to Mexico.
"It did not appear that this family was planning on going on a vacation, and the dogs were not being cared for," Brugos told ABCNews.com.
Brugos and fellow investigators issued a search warrant for the McStay's home and cars late Friday. They would not specify what, if anything, they found.
The family was last heard from Feb. 4, according to his Joseph McStay's younger brother Michael, who first reported the family missing Monday when no one picked up the family's phone.
"We've been strategizing to figure out where they might be," said Brugos. "We're working with border control to find out whether there is any activity on their passports, and whether they had any connection to narcotics or gangs, but it doesn't seem as though they do.
"It's an absolute mystery," he said.
Michael McStay said that his fountain business shipped worldwide regularly, but he wasn't sure whether the two young children even had passports yet.
Joseph McStay owns Earth Inspired Products, a company that designs interior decorative fountains, according to its Web site.
Michael and Joseph McStay's father, Patrick McStay, told ABCNews.com that he believes his son had done business in Tijuana, possibly as recently as this past December.
"I know he does business periodically," said Joseph McStay. "Some of the smaller fountains he offers are manufactured in Mexico, so he calls down there and has them sent to him."
Joseph McStay said he knew a lot about his son's business, because he was the initial investor in the company. He also said he knew his son had been to Mexico, or at least to the nearby border towns, late last year to pick up granite countertops for his home kitchen, which he was renovating.
"I don't want to say the words," said Joseph McStay when asked what he thought might have happened to his son, daughter-in-law and grandsons.
"This is one of the smartest young men you'll ever meet, he doesn't have a mean bone in his body," he said.
Friends and family of the McStays are planning to do a search of their own Saturday morning in hopes of gathering more information about the family's disappearance.
"Maybe people will see me, a blue collar working guy, a brother looking for his brother, and maybe they'll tell me something they don't want to tell the police," said Michael McStay.
Car of Missing San Diego Family Found Near Mexico Border
"He is not on a vacation," said Micheal McStay. "He wouldn't leave the dogs uncared for, and he's worked very hard to build his company up.
"He would not leave his business and not return e-mails or phone calls. It's an Internet-driven business," he said.
A voice mail box at the company's San Clemente, Calif., headquarters was full.
The outgoing message on the McStay's home answering machine is a chipper one, wishing callers to "have a nice day!"
"I just want my brother and my nephews and my sister-in-law back," said Michael McStay. "Those boys are adorable. We just want them all back."
Michael McStay said that he and his older brother, who is called Joey by those close to him, were best friends growing up in Texas.
"My brother is awesome," he said. "He is such a compassionate, caring person and so giving. He's likable and honest. That's why so many people are rattled by this."
Asked whether he could think of anyone who may have wanted to hurt his brother, Michael McStay said he coudln't think of anyone who didn't like his brother.
Speaking on behalf of his mother and father, who he said are both "a wreck," Michael said that while he's praying for the family's safe return, he's not naive.
"With what's going on in today's economy and how close his car was found to the border, the first thing I'm thinking is that it has something to do with money," said Michael McStay.
"People do stupid stuff for money, but I'm praying for the best."