Five Alameda County sheriff's investigators will travel to Yahualica in central Mexico early Wednesday as part of their ongoing effort to solve the saga of a teenage girl whose body was dumped behind a Castro Valley restaurant more than three years ago.

NBC11's Damian Trujillo will be traveling with the investigators and will update any findings on NBC11.com.

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Sgt. Scott Dudek said Tuesday that he and the other investigators hope that "the mystery will be solved" by their trip, which begins with a flight out of Oakland International Airport at 1 a.m. Wednesday.

The investigators will be in Mexico for three days and return Friday night.

The 5-foot 1-inch, 110-pound girl, who was dubbed the "Castro Valley Jane Doe" because no one knew who she was, was found inside a green canvas bag behind a Carrows restaurant in Castro Valley on May 1, 2003. She had a rag stuffed down her throat and had died of asphyxiation about 10 days earlier, police said.

Authorities estimated she was 15 to 17 years old and said it appeared she was a Latina.

Dudek said the investigation into her case "has really progressed considerably in the last six weeks" after authorities identified former Carrows employee Miguel Angel Nunez Castenada, 27, as a "person of interest."

Investigators believe that Castenada and the girl are from the same part of Mexico, had some type of relationship and may have lived together briefly in a house on Smalley Avenue in Hayward, Dudek said.

Dudek said authorities haven't confirmed the nature of the relationship, but his theory is that Castenada's and the girl's parents knew each other and that the pair had something of a brother-sister relationship, but Castenada wanted it to be more.

But Dudek said he doesn't know if Castenada was involved in the girl's death or what the motive was for the slaying.

Castenada was interviewed by sheriff's investigators in San Leandro about six weeks ago but fled the area when investigators and federal immigration authorities served search warrants at two homes in unincorporated Hayward to gather evidence in the case, Dudek said.

Castenada had previously been deported to Mexico and currently is in violation of his deportation order.

Dudek said authorities believe that Castenada is now in Yahualica but expect him to leave before the sheriff's team arrives tomorrow.

However, he said he thinks authorities will be able to arrest Castenada and extradite him to the U.S. if there's enough evidence to charge him because the case has been highly publicized and Mexican officials are outraged by the nature of the girl's death.

"The whole case is appalling to them and to us," Dudek said.

Dudek said the investigation also has been helped by witnesses who have come forward to say that the girl's name was either Adriana or Ariana.

He said investigators hope to learn her full name on this trip both for "humanitarian reasons" and for investigative purposes.

"Identifying her will be huge for the murder investigation," Dudek said.

He said sheriff's investigators will hold town hall and church meetings in the Yahualica area and meet with the town's mayor, police chief and other officials.

Dudek said authorities believe that both the girl and Castenada are from that area and that she left the region in March or April of 2003 either to come with him to the Bay Area or meet him in the Bay Area.

Yahualica is located 72 miles north of Guadalajara in the state of Jalisco.