Francisco Ortiz Franco was a tough editor dedicated to investigative journalism in this rough border city dominated by drug gangs, migrant smugglers, and organized crime.

When a colleague was killed in 1988 and another nearly slain in 1997, he insisted his crusading weekly newspaper, Zeta (search), would not back down.

That defiance apparently cost him his life Tuesday, when an unidentified assailant shot him dead in broad daylight.

The attack on Ortiz sparked an outcry from President Vicente Fox (search), international press groups and the publication's editorial board, which demanded a thorough investigation.

It also once again called attention to the dangers confronting journalists who work along the U.S.-Mexico border.

Ortiz was gunned down Tuesday as he left a clinic with his children, said Raul Gutierrez, spokesman for the state attorney general's office.

State investigators said a masked man armed with a pistol jumped from the passenger side of a black 4x4 Jeep and shot Ortiz at close range while he sat in the driver's seat of his blue Chevrolet Cobra. The Jeep then sped away.

Ortiz was hit four times in the head and neck, and died at the scene, said Francisco Castro Trenti, director of forensics for the Baja California (search) state attorney general's office. The children, ages 8 and 10, were unharmed.

Virginia Monje, 30, heard the shots from her kitchen.

"They sounded like fireworks," she said.

Monje went outside to see Ortiz's two young children running from the scene shouting "Papi! Papi!" They were later escorted away by people wearing plainclothes, she said.

Ortiz was a founder of Zeta, which since it began publishing in 1980 has been recognized for its reporting on the influence of drug traffickers in Tijuana.

His slaying was the latest in a series of attacks on the newspaper's leaders.

Zeta's co-founder, Hector Felix Miranda (search), was ambushed and killed on April 20, 1988. Two men were convicted in the shooting, one of them a bodyguard at a local race track owned by Jorge Hank Rhon (search), a businessman from one of Mexico's most powerful political families who is now running for mayor of Tijuana.

Since the killing, Zeta has published a full-page notice each week under Felix Miranda's name: "Jorge Hank Rhon: Why did your bodyguard Antonio Vera Palestina kill me?" the advertisement asks.

In 1997, the newspaper's publisher, Jesus Blancornelas (search), was badly wounded in a gangland-style attack that killed his bodyguard and driver, Luis Lauro Valero.

Shortly before he was shot, Blancornelas had written a column blaming David Barron Corona, a reputed lieutenant in the Arellano Felix drug gang (search), for a machine-gun slaying of two federal agents outside a Tijuana courthouse. Barron was among the men who attacked Blancornelas. He died in the crossfire.

Ortiz vowed at the time that such threats would not deter the staff.

"Obviously, we are not going to change," he said. "We are used to working on deep investigations, and that's not going to change."

Ortiz was among several journalists and government officials working with the Miami-based Inter-American Press Association (search) on an investigation into Felix Miranda's murder.

The association, or IAPA, issued a statement Tuesday afternoon expressing its "outrage" at Ortiz's killing.

IAPA President Jack Fuller, of the Tribune Publishing Co., said he was appalled by the slaying of "a journalist and family man who was outstanding not only as a publisher and person but also for having generously offered his help in a cause in our profession: that there be better investigation and that justice be done."

Although Ortiz's work did not focus primarily on drug traffickers, "he participated in numerous journalistic investigations," the newspaper's board of directors said in a news release posted on Zeta's Web site Tuesday night.

The board said while it "demands an investigation that leads to the killers' capture," it said it would not speculate on who was responsible "until we have sufficient information."

A nondescript house in a middle-class neighborhood of Tijuana that serves as the newspaper's headquarters was closed Tuesday night.

President Fox ordered federal officials to work with local authorities in order to resolve the investigation rapidly, a news release from Fox's office said.

In March, the IAPA noted that journalists on the border were being targeted for violence, and it worried that journalists might be frightened into self-censorship.

That statement followed the slaying of yet another journalist: Roberto Javier Mora Garcia, executive editor of El Manana newspaper in the northern border state of Nuevo Laredo, who was found stabbed more than 25 times outside his home.