The former CEO of Amazon Mexico was arrested for questioning and is considered the main suspect in his estranged wife's death.
Juan Carlos Garcia and Abril Perez Sagaon were going through a divorce and other troubles when she was ambushed in the Mexico City Airport on Monday as she left the city following a court hearing. She was shot in the head and neck by a motorcyclist before her two children's eyes.
Perez has obtained a restraining order against Garcia after he attacked her with a baseball bat while she was asleep earlier this year. He has served jail time for the offense and was released last month.
"He has enough money to hire a hitman," a relative said. "We have no doubt that it was him."
In 2014, Garcia was named the head of Amazon Mexico. He left his job three years later.