Six months ago, the slaying of black rights activist Marielle Franco shocked Brazil and prompted major demonstrations against the surging violence in Rio de Janeiro, where she served on the city council. Now, her widow is working overtime to preserve her memory, and says Franco remains a beacon of hope in a country still coming to terms with her brazen murder, which has not yet been solved. "I still feel a lot of pain. But I am waging a battle that has no end, so I really do not have time to mourn," Monica Benicio told AFP in the home she shared with Franco in Rio's middle-class neighborhood of Tijuca. Franco, who was 38, was murdered on March 14 in what appeared to be a professional hit in the center of Rio. A rare black city council member, Franco had become a prominent critic of police violence in Rio and what she said was the targeting of blacks in its teeming, poverty-stricken slums, or favelas. Franco also worked to defend the rights of the LGBTQ community. Colleagues believe the leftist politician was killed because she had angered police and underground paramilitary groups. At the entrance to Franco and Benicio's home, a purple heart sticker reads: "Marielle is here." Prints of the Mexican artist Frida Kahlo and the black US activist Angela Davis adorn the wall. "We used to live in the favela where we were born," says Benicio, explaining that the couple moved last year when Franco began her term as a city council member. Benicio, 32, now lives alone with her dog, but plans to move. In the meantime, she travels the world keeping Franco's memory alive at human rights events -- from Buenos Aires to Paris, Geneva, London and Athens. Benicio's schedule for September and October is packed. She has placed her studies to get a Master's on hold. "Pain is a kind of fuel. And it motivates me to see all over the world tell me our battle inspires them. Marielle is still a symbol of hope," she says. - 'Why Marielle?' - Seated barefoot on her sofa, sporting a black T-shirt emblazoned with the phrase "You matter to me" in Portuguese, Benicio wears an expression of determination tinged with sadness. Her life was turned upside down when Franco and her driver were gunned down. Authorities promised a swift and transparent probe but six months on, no real progress has been reported. "They always tell me, 'We are working on this. We are moving forward,' but without providing anything firm," she says. "As a wife, I feel a very particular kind of pain. But as a Brazilian, it also hurts to see that such an attack on democracy can go so long without a response." For Benicio, the country needs answers, and to learn what happened to Franco, "not for revenge, but so we have some sense of justice -- so we can ensure that there is still rule of law in Brazil." "More than who pulled the trigger and who paid for this murder, what intrigues me most is -- why Marielle?" she asks aloud. - Legacy - Benicio is well aware that Franco's work raised hackles in many corners of Rio. "It is clear that she bothered a lot of people. But I cannot imagine a specific reason for a crime of this magnitude," she said. Benicio, who says she too has been the target of threats, called on the Organization of American States to pressure the Brazilian government to provide information about Franco's case, and grant her police protection. In late August, she was given protection, though she declines to offer more details. With Brazil's general election less than a month away, Benicio says she is glad to see other black women, inspired by Franco, running for public office. "The people who killed Marielle wanted to silence everything she stood for, but these women have decided to come forward and seek their share of power," said Benicio. She chokes up when she recalls a ceremony at a school named for Franco in their old favela, called Mare. "A six-year-old girl told me she chose to wear her hair in an afro like Marielle, whereas before she used to wear it straight," Benicio said.