Assailants gunned down a Mexico City police commander outside his home in a drive-by shooting, officials said Tuesday.
Investigator Victor Hugo Moneda was killed as he was getting out of his car Monday night, the Mexico City prosecutor's office said in a statement.
The city's press office said no one has been arrested. It was unclear why Moneda was targeted, and authorities declined to give more information.
Mexican media reported that Moneda oversaw prosecutors in 16 districts, but city officials would not confirm that.
Scores of police, soldiers and judicial officials have been killed since the government launched a crackdown on organized crime two years ago.
Also Tuesday in the Gulf coast state of Tabasco, soldiers detained at least 10 police officers from four towns on suspicion of ties to drug traffickers, army Gen. Jaime Rufino Hernandez said.
Tabasco, which borders Guatemala, is considered a key trafficking area for U.S.-bound drugs from Central America.
Hernandez said the arrests were part of the government's "Operation Clean House," which has led to the arrest of more than a dozen high-ranking police and prosecution officials for allegedly passing information to the cartels.
In the northern city of Tijuana, across the border from San Diego, officials said four bodies were found early Tuesday.
Among them was a man clothed in a dress and with a flower in his hand. Another man was wearing a diaper and a pacifier on a string around his neck, according to an official with the Baja California state prosecutor's office who was not authorized to give his name.