NYPD sent out an alert on January 31 reporting Valerie Reyes as missing.
De Silva is a Venezuelan citizen and is reportedly in the country illegally as he overstayed his visa, according to CBS.
A source told the news outlet that Reyes was "killed at her residence" and the ex-boyfriend allegedly confessed to the murder to investigators.
Police said they have examined hundreds of hours of surveillance footage in the case and interviewed several potential witnesses.
'We are confident that the pursuit of justice for Valerie will be successful and we continue to work with the family to provide closure to this tragedy, ' the police statement said.More news: England Captain Tells West Indies Bowler: 'There's Nothing Wrong With Being Gay'
He was described as being cooperative during his interview.
Capt. Robert Berry says investigators "zeroed in" on DeSilva after he allegedly used Reyes' ATM card to withdraw cash multiple times after her death.
Vernon Geberth, a retired NYPD lieutenant-commander, told the Greenwich Time that he believes the killer crossed state lines, that the suitcase killing was "interpersonal", and suggested Reyes knew her killer and that the killing did not appear to be the work of a serial killer. "She didn't mention anything or no one specific". The night before, she made a frantic, prophetic phone call to her mother declaring: "I'm scared. I'm paranoid, mommy. I'm getting anxiety attacks'".
According to the New York Police Department, Reyes suffered from depression and anxiety.
"I asked about her ex-boyfriend". He said Reyes wasn't afraid of da Silva.More news: Chicago Cops Examine Phone Records, Bleach Bottle In 'Empire' Incident
She asked about her daughter's ex-boyfriend but still Reyes told her mother "no, it wasn't him". Officials said her hands and feet were bound when her body was found by highway workers on February 5.
Highway workers found her body in a wooded section of Greenwich, about 10 miles from New Rochelle.
The Connecticut Office of the Chief Medical Examiner has yet to release the autopsy results to rule the cause of death.
"At this unimaginably hard time, we are asking for love, support and respect to our family for the loss of my attractive daughter Valerie Reyes who is now resting in heaven", he said.
According to the Hartford Courant, a man who identified himself as Reyes' boyfriend wrote before she was found dead that people should contact him if they had any information about her disappearance.More news: Champions League: Defeat to PSG leaves Manchester United on brink of elimination