The Connecticut medical examiner says the woman found dead in a suitcase along a road in February had suffocated.
The office confirmed Monday that homicidal asphyxia was the cause of death of 24-year-old Valerie Reyes, of New Rochelle, New York. The office did not say whether she died before she was in the suitcase.
Her body was found by Greenwich town employees Feb. 5. She had been reported missing by her family six days prior.
Her ex-boyfriend, Javier Da Silva Rojas, of New York City, is being held on a federal charge of kidnapping resulting in death. If convicted, he could face the death penalty.
His attorneys haven't commented, but he told police after his arrest that Reyes fell and hit her head.