Updated

Over 300 girls and women have been brutally murdered over the past nine years just across the border in Juarez, Mexico, and after years of outcries U.S. authorities are joining the local investigation, which some say is fraught with incompetence and corruption.

A major step in the efforts to involve U.S. investigators occurred recently when Mexican authorities invited the head of El Paso's FBI office to Mexico to begin discussions about a binational task force.

"I hope the talks don't drag on too much longer because women are being murdered at an alarming rate over in Juarez," Hardric Crawford Jr., special agent in charge of the El Paso FBI, said.

Nearly 100 murders of women in Juarez are unlikely to be solved because of official incompetence and corruption, according to some Mexican officials familiar with the cases.

More than 320 girls and women have been killed in Juarez in the past nine years. About 90 of the murders involved methods associated with serial killers, according to FBI profilers and other experts who have examined the cases.

Even their looks were similar: young, dark hair and slender. One-fifth of them worked at U.S.-owned factories in the border town and were snatched going to or from work.

"If we're talking about a serial killer, it is entirely possible that person lives and works in El Paso then perpetrates his crimes over in Juarez," Crawford said.

Fox News acquired a list from the FBI of 25 American women who have disappeared in Juarez, but the agency said Mexican police work on the case has been so shoddy there is no way to tell if the listed women are among the Juarez dead.

No one has yet been convicted of any of the murders. Two bus drivers were arrested for eight of the murders but they later displayed burn wounds and claimed Mexican police tortured confessions out of them.

"Mexican police is corrupted and Mexican police is not scientific," Ester Chavez Cantu, an activist, said.

Norma Andrade De Garcia's 17-year-old daughter Lilia Alejandra was abducted and murdered.

"Unfortunately, our authorities, they don't have the desire or the capacity to stop this," De Garcia said.

The murders have included mutilation, torture, rape, stabbing, and shooting, and bodies have been found in clusters. The murders continue despite official assurances each time that the perpetrators have been caught.

Cover-ups, contaminated evidence, witness intimidation, and a corrupt system filled with incompetent officials -- eager to charge someone so they can declare the cases closed -- have sabotaged the investigations, critics say.

"We were asked to help plant evidence against two bus drivers who were charged with the murders," former Chihuahua state forensic chief Oscar Maynez Grijalva told the El Paso Times in a copyright story in its Sunday editions.

Maynez, who quit his job on Jan. 2 in disgust, said he has been threatened since he reported the corruption, but declined to give details.

"We are willing to investigate any of these allegations if proof is presented to us," Ortega said.

In January, Jorge Campos Murillo, a federal deputy attorney general in Mexico City, alleged that "juniors" -- sons of wealthy Mexican families -- were connected to some of the sex and torture killings.

Shortly thereafter, he was transferred to another section of the federal attorney general's office. He no longer answers questions about the Juarez cases.

Other Mexican federal law enforcement officials allege further that six people from the Juarez-El Paso region and Tijuana are having women abducted for orgies and then killed. They allege that the suspects are prominent men who cross the border regularly, are involved in major businesses, are associates of drug cartels and have ties to politicians in President Vicente Fox's administration.

In response to those allegations, Gabriela Lopez, spokeswoman for the federal attorney general's office in Mexico City, said, "These cases do not fall under [federal] jurisdiction ... the Chihuahua state attorney general's office is handling the cases."

And as far back as 1999, officials trying to solve the murders expressed frustration about the level of cooperation from local law enforcement.

"What we're seeing is many of the investigators disappear, be reassigned, other police come in ... kind of a lazy attitude toward solving the murders," Mary Benanti, editor of the El Paso Times said.

Fox News' Amy C. Sims and The Associated Press contributed to this report.