The Washington Post could not immediately reach the Hallandale Beach police for comment.
Police reports obtained by the Sentinel say that there was a spear at the foot of the bed and that during their fight, Galva is said to have grabbed the shaft as her boyfriend tried to pull her off the bed. At some point it snapped, sending the blade plunging into Galva's chest, according to the police reports obtained by the Sentinel. Crespo told police he pulled the blade from his girlfriend's chest and tried to stop the bleeding, the Sentinel reported, while a friend of Galva's called police and performed CPR.
Investigators asked Amazon to hand over any details that the two Amazon Echo devices in the house recorded between July 11 at 12 a.m. and July 12 at 11:59 p.m. according to the Sentinel. (Amazon chief executive Jeff Bezos owns The Washington Post.)
In justifying probable cause for a warrant, police wrote, "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."
From a legal perspective, the investigative practice is straightforward, said Princeton University professor Jonathan Mayer.
"Law enforcement can access smart-speaker recordings after obtaining a search warrant," said Mayer, who served as chief technologist of the Federal Communications Commission Enforcement Bureau.
In a statement, Amazon spokeswoman Faith Eischen told The Washington Post that the company "does not disclose customer information in response to government demands unless we're required to do so to comply with a legally valid and binding order." She added that the company "objects to overbroad or otherwise inappropriate demands as a matter of course."
Crespo's lawyer, William DiRenzo, told the Sentinel in July: "There are a lot of unanswered questions at this point in time. Our hope is once the investigation is complete, he will be exonerated."
DiRenzo did not respond to requests for comment on Saturday.
Amazon Echoes have figured in a 2018 New Hampshire murder case and another investigation in Arkansas that ended with a judge dismissing the case. In both cases, Amazon pushed back against demands that it release user data.
Police have turned to other technologies as well in trying to solve crimes. The data collected from Fitbits to electronic key fobs to Ring doorbells have been requested by police to aid investigations.
Ring, in particular, has openly partnered with local police and allows them to access the camera feeds captured and transmitted by their devices, prompting concerns about surveillance overreach.
The use of such devices for investigations will only increase as the technology becomes more pervasive in everyday life, said Andrew Ferguson, a law professor at the University of the District of Columbia.
Ferguson warned that judges, who assess whether police have probable cause to obtain such warrants, will increasingly need to decide whether there's a valid reason to obtain a person's personal data, which can be "incredibly revealing of who we are." Because Alexa is only supposed to activate and record when given a specific voice command, it was unclear whether obtaining a blanket warrant to examine a device's transmissions could amount to a "fishing expedition," Ferguson said.
"We live in a world where we have these little digital spies listening to us in our homes, in our cars, in our phones," Ferguson said. "It is going to become pretty commonplace that law enforcement is going to request as much digital evidence as they can about us using the legal means available."
"We have really created a privacy-invasive world because of consumer convenience," he said.