Olea said the ex-husband is still at large, and a reward will be offered for his arrest, but his mother – who shares the home with her son – has been arrested.
Police have said they are treating the crime as "femicide" – or the targeted murder of a woman because of her gender. Such killings have increased markedly over the past year across Mexico.
The government of Taxco said in a statement that it "vigorously condemns the cowardly murder of Magdalena Aguilar, which irreparably hurts our society."
"From the time her disappearance was known, we have offered all the support to Magdalena's family, with who we have always shown solidarity and to whom we show our unconditional support," it said.
It added that much work "needs to be done to protect and rebuild the social fabric of our municipality."
- AP