Given the task definition and input, reply with output. In this task, you are given a text of many news articles seperated by special token "|||||". Your task is to summarize them.

FILE - In this Tuesday, Feb. 27, 2018 file photo ThruVision suicide vest-detection technology reveals a suspicious object on a man, at left, during a Transportation Security Administration demonstration... (Associated Press) 
  
 FILE - In this Tuesday, Feb. 27, 2018 file photo ThruVision suicide vest-detection technology reveals a suspicious object on a man, at left, during a Transportation Security Administration demonstration in New York's Penn Station. Los Angeles is poised to have the first mass transit system in the U.S.... (Associated Press) 
  
 LOS ANGELES (AP) — Los Angeles' subway will become the first mass transit system in the U.S. to install body scanners that screen passengers for weapons and explosives, officials said Tuesday. 
  
 The deployment of the portable scanners, which project waves to do full-body screenings of passengers walking through a station without slowing them down, will happen in the coming months, said Alex Wiggins, who runs the Los Angeles County Metropolitan Transportation Authority's law enforcement division. 
  
 The machines scan for metallic and non-metallic objects on a person's body, can detect suspicious items from 30 feet (9 meters) away and have the capability of scanning more than 2,000 passengers per hour. 
  
 "We're dealing with persistent threats to our transportation systems in our country," said Transportation Security Administration Administrator David Pekoske. "Our job is to ensure security in the transportation systems so that a terrorist incident does not happen on our watch." 
  
 On Tuesday, Pekoske and other officials demonstrated the new machines, which are being purchased from Thruvision, which is headquartered in the United Kingdom. 
  
 "We're looking specifically for weapons that have the ability to cause a mass-casualty event," Wiggins said. "We're looking for explosive vests, we're looking for assault rifles. We're not necessarily looking for smaller weapons that don't have the ability to inflict mass casualties." 
  
 In addition to the Thruvision scanners, the agency is also planning to purchase other body scanners — which resemble white television cameras on tripods — that have the ability to move around and hone in on specific people and angles, Wiggins said. 
  
 "We really want to be effective and we need the ability to have a fixed field of view, but we also need to be able to move that field of view as necessary," Wiggins said. "Deploying these technologies together gives us that accuracy and minimizes any delays." 
  
 Wiggins would not say how many of the machines were being purchased, but said they would be rolled out in subway stations in the "coming months." Employees and police officers first have to be trained on how to use the equipment. 
  
 Signs will be posted at stations warning passengers they are subject to body scanner screening. The screening process is voluntary, Wiggins said, but customers who choose not to be screened won't be able to ride on the subway. 
  
 But some passengers saw the screening as an added layer of security. 
  
 "I guess it is a good, precautionary thing," Andrea Kirsh said, a 22-year-old student from Corvallis, Oregon, who was traveling through Los Angeles' Union Station on Tuesday. "It makes me feel safe. As a civilian I think we often don't know what to look for or what we would be looking for." 
  
 Passengers who rode down an escalator to ride the Metro Red Line at Union Station in Los Angeles on Tuesday were screened as Pekoske and other officials looked on. But after the news conference and media demonstration, officials packed up the equipment and carted it off. 
  
 The TSA tested body scanners in New York's Penn Station in February and has also conducted tests at Union Station in Washington, D.C., and at a New Jersey Transit station during the 2014 Super Bowl. 
  
 In December, a Bangladeshi immigrant injured himself by setting off a crude pipe bomb strapped to his chest in a subway passageway near Times Square in New York City. 
  
 Metro has previously tested several different types of body scanners, including airport-style screening systems where passengers walk through a scanner. The pilot program was meant to evaluate the accuracy and capacity of the portable machines. 
  
 About 150,000 passengers ride on Metro's Red Line daily and the subway system counted more than 112 million rides last year, officials said. 
  
 ___ 
  
 Follow Michael Balsamo on Twitter at www.twitter.com/MikeBalsamo1 . ||||| (CNN) — Don't worry, Los Angeles commuters, your time rushing through the metro system won't be held up by these body scanners. 
  
 Instead, these new high-tech scanners, at the bottom of the escalators, will scan you as you walk by. They scan your naturally occurring body waves looking for any indication of concealed weapons or explosive devices. 
  
 The Transportation Security Administration partnered with LA Metro to test the portable passenger screening devices and announced on Tuesday that Metro will be the first in the nation to equip its surface transportation agency with them. 
  
 This the the front view of the scanner. KTLA 
  
 "Metro has been an industry leader in testing new technologies to meet the evolving threat to our nation's public transportation infrastructure," said Sheila Kuehl, LA County supervisor and Metro Board chairwoman, in a statement. 
  
 "This new technology will augment our aggressive safety and security posture and help us proactively deter potential attacks to our system." 
  
 So how do they work? 
  
 They scan your body for objects that are blocking your naturally produced body waves. Both metallic and nonmetallic objects can be picked up by the scanner. 
  
 "When an object is hidden in clothing or strapped to a person, these waves are blocked and detected by the system's software," reads a news release from LA Metro . "The software generates generic avatars and creates either a black spot on the area of the body where the item is concealed or overlays a color indicator." 
  
 No radiation is emitted, and the scanners will not display anatomical details. The technology has been tested this past year at the 7th Street/Metro Center Station. ||||| Another view, from L.A. Times transportation reporter Laura Nelson: 
  
 Here’s the new body scan technology that @metrolosangeles has purchased, designed to detect suicide vests and other wearable explosives. The black box on the left-hand side of the screen shows a ceramic plate beneath a woman’s shirt as she comes down the escalator. pic.twitter.com/fWL0q7uEq3 — Laura J. Nelson 🦅 (@laura_nelson) August 14, 2018 
  
 A media event was held today at Union Station. Here is the news release from Metro and the TSA: 
  
 The Transportation Security Administration (TSA) has partnered with Metro to deploy a new advanced portable passenger screening technology that will help detect weapon and explosive device security threats on the county’s transit system. 
  
 Metro is the first surface transportation agency in the nation to purchase such an advanced, high-tech security device to help keep transit riders safe from person-borne improvised explosive devices or other weapons that are intended to cause mass casualties. 
  
 Following a series of tests over the last year of TSA-vetted and approved security technologies at its stations, Metro has purchased several Thruvision TAC-TS4 
  
 portable terahertz millimeter wave passenger screening devices. The units can be placed at locations throughout the Metro system and are equipped with software that quickly and unobtrusively screens individuals for concealed threats. The units can identify both metallic and non-metallic objects. 
  
 The devices identify objects that block the naturally-occurring waves produced by a person’s body. When an object is hidden in clothing or strapped to a person, these waves are blocked and detected by the system’s software. The software generates generic avatars and creates either a black spot on the area of the body where the item is concealed or overlays a color indicator. The technology does not emit radiation of any kind and no anatomical details are displayed. The device allows law enforcement agents and Metro Security to screen rail and bus patrons without disrupting foot traffic and to take decisive, pre-emptive action if suspicious items are found. 
  
 “TSA applauds the leadership of L.A. Metro for its proactive efforts to evaluate, procure and use state-of-the-art technology designed to detect potential threats to the transit system,” said TSA Administrator Pekoske. “TSA is pleased to have been a partner during the evaluation and testing process, which ultimately led to the purchase of a recommended system to help detect and deter potential acts of terrorism while keeping the traveling public safe.” 
  
 The Thruvision technology was tested extensively by TSA. Metro tested the technology at its 7th Street/Metro Center Station over the last year. 
  
 “Metro has been an industry leader in testing new technologies to meet the evolving threat to our nation’s public transportation infrastructure,” said Sheila Kuehl, L.A. County Supervisor and Metro Board Chair. “This new technology will augment our aggressive safety and security posture and help us proactively deter potential attacks to our system.” 
  
 For additional information about Metro’s Safety and Security Program, visit www.metro.net/safety. For more photos, please click here. Here is video from the press event: 
  
 Like this: Like Loading... ||||| Later this year, the Metropolitan Transportation Authority will deploy several portable scanners that can be moved to any of the system’s 93 subway and light-rail stations. The devices will be used in response to terrorism threats, or to scan large crowds at a station near a protest or a sporting event, officials said. |||||

All humans emit body waves, but if they're concealing an object under their clothes, that object blocks the waves—exactly what the Transportation Security Administration is banking on with the installation of the country's first body scanners in a transit agency. The subway system getting the first crack at these portable passenger screening devices, per CNN: the LA Metro, which can place the high-tech scanners at the bottom of escalators or at station entrances to "quickly and unobtrusively screen individuals for concealed threats," per the Source blog. The Thruvision scanners, which the New York Times describes as wheeled devices looking like "the sort of black laminate cases that musicians lug around on tour," can pick up both metallic and nonmetallic objects from up to 30 feet away. The $100,000 devices are able to scan more than 2,000 people an hour. "We're looking specifically for weapons that have the ability to cause a mass-casualty event," Alex Wiggins, head of the LA County MTA's law enforcement unit, tells the AP. "We're not necessarily looking for smaller weapons that don't have the ability to inflict mass casualties." He adds, per the Los Angeles Times, that signs will warn about the scanners, and commuters can "opt out" (though they then won't be able to ride the subway). The scanners don't emit radiation or display "anatomical details," and they won't slow down traffic—they'll simply scan people streaming by. "Most people won't even know they're being scanned," an LA Metro rep tells the New York Times, though one rider wonders if the system will lead to an uptick in police harassment or "false positives." "But if we don't even notice it, and they use it in a responsible way, then I think it's a good thing," the commuter adds.