Claudia Sheinbaum was sworn into office Wednesday as the first elected female mayor of Mexico City and immediately announced she would dissolve the riot police.
"The police are there to protect the people, and we don't need a police force to repress them," said Sheinbaum.
Sheinbaum pledged to build cable cars to impoverished slums, and improve bus and subway service.
She also said replacement housing would be built for people who lost their homes and apartments in the 2017 earthquakes.
The previous administration had offered loans for rebuilding, but residents wanted the government to pay for the new units.
Her key promises included reducing crime and enforcing zoning laws, a hot-button issue in the constantly growing megalopolis, where developers routinely build bigger buildings than zoning rules allow.
Sheinbaum, who has a doctorate in environmental engineering, did post-doctoral research at Lawrence Berkeley National Laboratory in California and is a former member of the U.N. Intergovernmental Panel on Climate Change.
She's also a longtime associate of new leftist President Andres Manuel Lopez Obrador.
The only previous female governor for the city of 9 million was Rosario Robles, who was appointed in 1999 to serve out the remaining year term of Cuauhtemoc Cardenas when he ran unsuccessfully for the presidency.