MEXICO CITY (AP) — Mexico City officials said Sunday they are pursuing all lines of investigation into the killing of a photojournalist whose body was found along with four slain women in the capital, where he had fled because of harassment in the state he covered.

Investigators are following protocols for crimes against journalists and crimes against women, as well as looking at robbery as a possible motive, Mexico City prosecutor Rodolfo Rios Garza said in news conference.

But journalism and human rights activists were alarmed by Rios' comments, saying Ruben Espinosa's work and the threats that drove him out of the Gulf Coast state of Veracruz should be the main line of investigation. He had worked in the state for eight years, including for prominent newsmagazine Proceso, before fleeing to Mexico City.

Rios never acknowledged that Espinosa was seeking refuge in Mexico City, saying he came to the capital for "professional opportunities."

When dealing with journalists' killings, authorities in Mexico are often quick to discard their work as a motive, even though the country is the most dangerous in Latin America for reporters. In large swaths of the country, crime and corruption are never reported, as the media has been bought or intimidated into silence.

"I feel there is a disdain toward investigating the journalistic motives or even motives that had to do with his displacement," said Dario Ramirez, director of the Article 19 free press advocacy group. "The issue is that he was at risk and after a month he was assassinated. These are coincidences that can't be discarded by saying he was in the wrong place at the wrong time."

Reporters at the news conference asked if the events that drove Espinosa into self-exile in June were being investigated and whether Veracruz Gov. Javier Duarte would be asked to give a deposition.

Rios only repeated that all lines of investigation are being pursued, including his work as a journalist in Veracruz.

Espinosa had said in interviews that he was harassed over several years while covering events in Veracruz, including once being told to stop taking photos of students detained during a protest in 2012, the same year another Proceso journalist, Regina Martinez, was killed. Her role as an investigative journalist writing about government corruption was never considered as a motive for her killing. Instead, state officials said it was robbery.

"Stop taking photos if you don't want to end up like Regina," Espinosa said he was told by a government representative controlling the crowd.

Another time, Espinosa said Duarte offered him money to drop a complaint after he was beaten by state police, according to Proceso magazine. He refused.

Espinosa fled the capital, Xalapa, in June after he said that unknown people were following him, taking his photograph and harassing him outside his home. A few days earlier, he had placed a plaque at a Xalapa plaza renaming it "Regina Martinez Plaza" as a protest to the government's handling of her case.

"We're saying loud and clear that we want Duarte in jail, that no more journalists, not a single one, can be assassinated in Veracruz," said Neftali Granados, a Veracruz student speaking at a protest rally in Mexico City that drew about 200 people.

Duarte issued a statement Sunday saying he lamented the "aberrant" killings in Mexico City and is confident that prosecutors will solve the case as soon as possible.

In June, he accused some reporters of being involved in organized crime.

"We all know who is involved in the underworld," Duarte said. "There's no reason to confuse freedom of expression with representing the expression of criminals via the media."

Veracruz has been a dangerous state for reporters, with 11 journalists killed just in current administration of Duarte that started in 2010. Two more, including Espinosa, have been killed outside of the state and three have gone missing.

The five bodies were found late Friday in an apartment in a middle-class Mexico City neighborhood. The building was in range of several security cameras on the street and Rios said they have video evidence in the crime, though he did not elaborate. The attackers would have had to go through two doors to get inside, and neither had signs of damage or break in.

Rios also said the apartment was ransacked and robbed. Three of the women lived there and a fourth was the housekeeper.

Rios did not identify the other victims, only giving their ages as 18, 29, 32 and 40. All were shot in the head with a 9 mm weapon. Espinosa sustained severe injuries to his face before he was killed, Ramirez said.

Ramirez said Espinosa knew one of the women from working in Veracruz.

Ramirez said that Article 19 had published an alert about Espinosa on June 15 after he arrived in Mexico City. He confirmed that Espinosa had not sought official protection or help from the federal government agency created to protect journalists and human rights workers who are under threat. He said Espinosa had more confidence in civil agencies like Article 19 and his friends for protection.

It was the first time a journalist was killed in Mexico City since 2006, when Jose Manuel Nava Sanchez, a columnist for El Sol de Mexico, was found stabbed to death in his apartment with valuables missing, according to the Committee to Protect Journalists.

Article 19 said Espinosa's death marks a new milestone in violence against the press because he was the first journalist to be killed in exile in the capital. The agency said there are dozens of journalists from all over Mexico taking refuge in Mexico City.

"The level of impunity is what allowed this to happen," said a journalist in Mexico City who also had to flee Veracruz. "Displaced journalists used to come to Mexico City as an island of protection. Now there is no place to go, no place to run."

The journalist did not want to be named for security reasons.