An estimated hundreds of thousands of rape kits sit untested in police departments nationwide, according to the Joyful Heart Foundation, a group that helps sexual assault victims. A Denver cardiologist has been charged with drugging and sexually assaulting a string of women he met on the dating apps Hinge and Tinder, court papers allege. Stephen Matthews, 35, was first arrested March 22 based on one victim's disturbing accusations. Widespread reports of the allegations prompted nine other women to come forward, officials said. On Monday, Matthews was arrested on the new charges outside the Denver District Courthouse after making an appearance on the initial case.

Police in Florida believe recordings from a murder suspect's Amazon Echo may contain crucial information as they investigate an alleged argument at the man's home that ended in his girlfriend's death. Adam Reechard Crespo, 43, is charged with murder in connection to the July death of Silvia Galva, who died after suffering a stab wound to the chest. The Broward County Sheriff's Office believes Crespo's Echo - a smart speaker that connects to the Amazon voice-activated personal assistant Alexa - may have been a witness to the crime and obtained search warrants for all the device's recordings. Hallandale Beach Police Department spokesman Sgt Pedro Abut told the Sun-Sentinel that the department has received the recordings and is "in the process of analysing the information that was sent to us". The police department did not immediately return NBC News' request for comment on Saturday.

Elon Musk has sounded off on AI various times, and how it can pose a massive threat to the world. At a meeting of the nation's governors, Elon Musk warned that artificial intelligence was "the greatest risk we face as a civilization". As a result of his deep involvement in the tech industry, Elon Musk said he "[has] access to the very most cutting edge AI," and that "people should be really concerned about it." In a tweet, Elon Musk stated that AI was "potentially more dangerous than nukes". Elon Musk is also concerned that AI can be used in a warfare scenario, by being able to create massive amounts of fake news (i.e. in a propaganda scheme to push a certain ideology), fake press releases, and manipulating information in general.

A former NASA engineer has created a hot tub with a difference, filled with liquid sand that acts the same way as water, allowing him to float and splash around. Mark Rober, 37, from Orange County, California, is known for his quirky science based videos on YouTube. And for his latest post, he decided to customize a hot tub so he could experience the sensation of floating in liquid sand, known in science as a fluidized air bed. Experiment: During the video, Mark reveals how he created'liquified sand' using an old hot tub, copper pipes and pressurized air'I am sitting in a hot tub filled to the brim with solid sand. This is one of the coolest things ever,' Mark told the camera as he sat in his creation.

It's a fair question in light of attempts by authorities investigating the slaying of an Arkansas man to obtain voice recordings collected by an Amazon Echo speaker and its Alexa digital assistant. Yet the popularity and capabilities of voice-enabled products such as the Echo continue to grow. At the CES gadget show in Las Vegas, which opened Thursday, Whirlpool, Samsung and other manufacturers are unveiling new ways to use voice services to control laundry machines, refrigerators and other home systems. John Herrington, senior vice president of Samsung Electronics America, unveils new refrigerators with Family Hub 2.0 during a Samsung news conference before CES International, Wednesday, Jan. 4, 2017, in Las Vegas. Family Hub 2.0 features an interface on the refrigerator with apps that can be controlled by voice recognition.

Authorities investigating the death of an Arkansas man whose body was found in a hot tub want to expand the probe to include a new kind of evidence: any comments overheard by the suspect's Amazon Echo smart speaker. Amazon said it objects to "overbroad" requests as a matter of practice, but prosecutors insist their idea is rooted in a legal precedent that's "as old as Methuselah." The issue emerged in the slaying of Victor Collins, who was found floating face-up last year in the hot tub at a friend's home in Bentonville, about 150 miles northwest of Little Rock. The friend, James Andrew Bates, was later charged with murder. Prosecutors have asked the court to force Amazon to provide data from the Echo that could reveal more clues about the night of Nov. 22, 2015, when Collins was apparently strangled and drowned. Benton County Prosecuting Attorney Nathan Smith said yesterday that he has no idea if the device recorded anything related to the death.

FILE - This July 29, 2015, file photo shows Amazon's Echo speaker, which responds to voice commands, in New York. A prosecutor investigating the death of a man whose body was found in a hot tub wants to expand the probe to include a potential new kind of evidence: the suspect's Amazon Echo smart speaker. Amazon has called the request "overbroad or otherwise inappropriate." FILE - This July 29, 2015, file photo shows Amazon's Echo speaker, which responds to voice commands, in New York. A prosecutor investigating the death of a man whose body was found in a hot tub wants to expand the probe to include a potential new kind of evidence: the suspect's Amazon Echo smart speaker.

Cops have asked Amazon to reveal any audio it might have stored after a man is murdered in a hot tub in Arkansas. The crime, committed in Bentonville, happened in a hot tub, but police found an Echo at the scene and wanted Amazon to unlock any audio it has sent to its cloud servers. Amazon refused, demanding a warrant first. Over on Slashdot the argument started quickly about the merits of allowing a device into your home that can listen to every word you say. Amazon, for its part, assured journalists at the UK launch of the product that it only ever saves audio directly after the keyword is spoken to trigger the unit.

US police investigating a murder have tussled with Amazon over access to data gathered by one of its Echo speakers. The voice-controlled device was found near to a hot tub where the victim was found dead amid signs of a struggle. According to court filings, Amazon was issued with two search warrants but refused to share information sent by the smart device to its servers. However, the police said a detective found a way to extract data from the device itself. The accused killer has yet to be put on trial and it is not clear whether the information ultimately proved useful to the investigation.

US police investigating a murder have tussled with Amazon over access to data gathered by one of its Echo speakers. The voice-controlled device was found near to a hot tub where the victim was found dead amid signs of a struggle. According to court filings, Amazon was issued with two search warrants but refused to share information sent by the smart device to its servers. However, the police said a detective found a way to extract data from the device itself. The accused killer has yet to be put on trial and it is not clear whether the information ultimately proved useful to the investigation.