Calling the witness – Alexa. Police in Florida are investigating whether they have stumbled on a silent witness to a possible murder and are trying to get the truth from “her”.

Sylvia Galva Crespo, 32, was killed by a spear to the chest at home in Hallandale Beach, Florida, north of Miami, in July, which her husband, Adam Crespo, 43, has portrayed as a mysterious accident.

But police believe the Amazon Echo smart speaker devices in the home, known as Alexa because of the common “wake” word used to activate them, may have heard and recorded something relevant during the fatal altercation when the couple argued after a night out, the Sun Sentinel reported.

“It is believed that evidence of crimes, audio recordings capturing the attack on victim Silvia Crespo that occurred in the main bedroom … may be found on the server maintained by or for Amazon,” police wrote in a legal filing.

Adam Crespo is charged with second-degree murder.

“We did receive recordings, and we are in the process of analyzing the information that was sent to us,” the Hallandale Beach police department spokesman, Sgt Pedro Abut, told the Sun Sentinel.

When police were called to the home in July they found Sylvia Galva Crespo bleeding profusely, with a friend of the woman, who had been out with the couple, trying to save her life. Adam Crespo said the spear had snapped during the altercation and the 12in blade had somehow pierced his wife’s chest. He pulled the blade out “hoping it was not too bad”, but she died.

The friend said she heard the couple arguing but did not know what it was about.

Investigators now wonder if there was any chance “Alexa” was “awoken” at any time during the incident and recorded anything useful to getting to the bottom of the woman’s gruesome death.

Items using smart technology, often known as “the internet of things”, do have a certain capacity to eavesdrop in some circumstances and have come up in criminal cases before.

Crespo is free on $65,000 bond and denies the offense. The case continues.