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. Adam Crespo is charged with second-degree murder. When police were called to the home in July they...