let's get the story now from nbc's tammy leitner. >> drop the knife! >> reporter: tonight, newly released dramatic video showing an intense standoff between los angeles police officers and this man, holding a woman hostage at knifepoint outside a homeless center. 32-year-old guillermo perez, a known gang member with an extensive rap sheet, ignores repeated commands to drop the knife and police fire nonlethal beanbag rounds. he grabs elizabeth tolleson and holds the knife to her neck. he cuts her throat and police take action. they fire rounds at perez. two strike and kill tolleson. >> police had no regard for my mother's life. >> reporter: her children filed a wrongful death lawsuit against the city of los angeles. this incident just weeks before another fatal police shooting of an innocent bystander. when an lapd officer shot and killed a store manager at trader joe's while exchanging gunfire with a suspect. these fatal shootings the first time lapd has killed a hostage or bystander in 13 years. >> the average number of rounds fired by officers have i

nbc's tammy leitner has late details. >> this is our suspect. >> reporter: an intense manhunt coming to a dramatic end. >> i think he shot himself. >> reporter: joseph james pappas wanted for a revenge killing of a doctor in broad light killed himself after a stand off with police. the 65-year-old was wearing body armor and had two guns on him believing he may have been preparing for a shootout after 15 days on the run. >> you normally don't put on a bulletproof vest when you think about suicide. >> reporter: houston police closed in on pappas after a city employee spotted him on a park bench. >> i just thank god we don't have a dead cop back here. this man, we know he was a very experienced marksman. >> reporter: two weeks ago pappas who worked in law enforcement shot former george hw bush cardiologist dr. mark hausknecht in the head, chest and arm as he rode his bike to work. the shooting carefully planned. police say he collected an extensive intelligence file on dr. hausknecht with information on his house, work, cars and names of other employees at the texas medical center. >> h

our tammy leitner reports on the growing concern and the increasing toll. >> reporter: nine beloved bottle nose dolphins have washed up dead in the last week, the latest victims of the toxic red tide along florida's west coast. >> we had a few rescues but we're seeing a lot of mortality. >> reporter: while the algae bloom happens almost annually, this is the longest outbreak in nearly a decade killing turtles, manties and sea life. >> we picked up 16 turtles in the last 24 hours. doesn't feel like there is an end in sight. >> reporter: the red tide hitting beaches from tampa to naples. it's an algae that can grow out of control and produce dangerous toxins. also poisoning florida's water, blue green algae, choking fresh water canals and waterways inland. it's caused by pesticides and urban run off aggravated by dams releasing water from the lake. >> just the idea of being around something that could make my son sick is really a big concern of mine. >> reporter: the water smells terrible and threatens people, too. causing respiratory problems, skin rashes and nausea. >> i get whiffs every n

tammy leitner, nbc news. >>> the vatican and pope francis under fire tonight for staying silent 24 hours after that bombshell grand jury report we told you about last night. it accuses the church of protecting over 300 predator priests in pennsylvania over a period of decades. nbc's anne thompson with reaction tonight from survivors. >> reporter: tonight, survivors of priest sexual abuse like sean dockerty see a glimmer of hope. >> if this report doesn't eliminate the statute of limitations, what it going to take to do that? >> reporter: for this pennsylvania state representative, it's a crusade. he was raped by a priest. >> victims should have any amount of time to come forward when they're ready. >> reporter: the grand jury report detailed a litany of alleged crimes. a priest who abused five girls in one family. another who raped at least 15 boys. and still another accused priest who left the clergy and the diocese recommended him for a job at walt disney world. is this just a pennsylvania problem? >> no, i don't think it's a pennsylvania problem solely at all. >> reporter: he was one

tammy leitner, nbc news. >>> coming up tonight, was it excessive force? an 11-year-old tased for allegedly shoplifting. her outraged mother is speaking out. we'll have it. >>> an outraged mother is speaking out after her 11-year-old daughter was tasered by an off-duty police officer for allegedly shoplifting from a cincinnati super market. nbc's blake mccoy has that story tonight. >> why would they even do such a thing? >> reporter: donna gowdy describes the moment her 11-year-old daughter was tased. >> she fell down and rolled over and was shivering. >> reporter: doneshia was caught shoplifting snacks from this kroger monday night. >> i got up and i couldn't really breathe. >> i'm not saying what she did was cool. you know, i'm not vouching for that but the way he went about it was totally wrong. >> reporter: the security guard was an off duty cincinnati cop currently on restricted duty following the incident. police policy states a taser may be used on a suspect over age 7 or under 70 but also that officers should consider the severity of the crime. the

tammy leitner, nbc news. re >>> a quick and then we're back with good news about the homeless man that we introduced you to last week that got a helping hand from a video seen by millions. ever lop plap with type 2 diabetes.aduls it's one pill a day and although it's not a weight-loss drug, it may help you lose weight. do not take if allergic to farxiga. if you experience symptoms of a serious allergic reaction such as rash, swelling, difficulty breathing or swallowing, stop taking and seek medical help right away. do not take farxiga if you have severe kidney problems, are on dialysis, or have bladder cancer. tell your doctor right away if you have blood or red color in your urine or pain while you urinate. farxiga can cause serious side effects including dehydration, genital yeast infections in women and men, serious urinary tract infections, low blood sugar, and kidney problems. stop taking farxiga and call your doctor right away if you have signs of ketoacidosis... ...which is serious and may lead to deat

tammy leitner, nbc news, college station, texas. >>> coming up, protesting a supreme court nominee. up next, the message from demonstrators in san francisco and across the country against nominee brett kavanaugh. welcome to the xfinity store. thanks, janet. it's my happy place. you can learn how to switch to xfinity mobile, a new wireless network that saves you cash. and you can get 5 lines of talk and text included with your internet. and over here i'm having my birthday party. dj fluffernutter, hit it! ♪ dj fluffernutter simple. easy. awesome. ask how to get $300 back when you sign up for xfinity mobile, and purchase a new samsung phone. visit your local xfinity store today. >>> we continue to follow breaking news out of lake county, where a new fire is burning. firefighters are on the scene at highway 20 and new long valley road. that's in clear lake oaks. details are still very limited at this time, but cal fire is calling the fire the cash fire. 105 acres have burned but crews are worried it could spread quickly to as many as 400 acres. containment right now, 20%. the good news

tammy leitner, nbc news, las vegas. >>> coming up, violence at a bay area house party.g that has police now looking for a suspect. welcome to the xfinity store. thanks, janet. it's my happy place. you can learn how to switch to xfinity mobile, a new wireless network that saves you cash. and you can get 5 lines of talk and text included with your internet. and over here i'm having my birthday party. dj fluffernutter, hit it! ♪ dj fluffernutter simple. easy. awesome. ask how to get $300 back when you sign up for xfinity mobile, and purchase a new samsung phone. visit your local xfinity store today. while oti'm the only ones servthat has the bowlsff, to serve something different. i mean, just look at my teriyaki bowls. choose from steak or chicken, covered in teriyaki sauce, plus your choice of white or brown rice. what about these bowls jack? hey! you got some pretty nice bowls there. and so does dan! thanks jack! those are some nice bowls. everyone's gonna want to get their hands on jack's bowls. try my bowls! see that right there? you can't say that. what? i was just sa

nbc's tammy leitner explains the confusion and why this could happen to any family. > reporter: it's a parent's worst nightmare. 9-year-old carter gray and his 7-year-old sister eta were flying for the very first time as accompanied minors. they had just visited their grandparents and were flying home to orlando when severe weather hit. that's when the plane got diverted and had to land in atlanta. coming up at nightly news hear from their parents who were furious after the pla landed in atlanta yet no one from the airline called them. theyidn't hear from their kids for hours, and they didn't hear from anyone at the airline. that can happen to any parent with hundreds of thousands of kids flying every single year and no federal guidelines on unaccompanied minors. ghck to you guys. >> all r tammy leitner reporting. >> concern tonight after ev elevateds of lead were found in the drinking water at more than 80 montgomery county public schools. the school system says the problem will be fixed before classes start. news 4's chris gordon reports. >> reporter: how safe is the water in your

nbc's tammy leitner is explaining how this unlikely pairing is helping to keep some of the nation's most sensitive information safe. >> reporter: a new dark side to sin city. beneath the glimmering lights and noisy casinos, hackers. the best in the world take aim at america's military. for one night only, the department of defense recruiting the world's top 100 hackers to try to find vulnerabilities before america's adversaries like russia and china. describe what you just found. >> it was essentially where all the military is located, if they are active duty. >> reporter: it is called a bug bounty, cash paid out for exposing gaps in the marines' public websites. what is your reaction to what he just found? >> i have work to do as soon as i get back to ft. meade. >> reporter: during the night, it happened over and over, 75 times. >> i'm looking for files that may contain data such as databases. >> reporter: we have not seen this yet. one of the hackers has been asked to stop what he is doing after gaining access to a secured site. now with marines standing around watching, he is being al

tammy leitner has late breaking details. >> reporter: tonight, emergency crews rushing to the scene of a plane crash in northwest mexico. the plane, holding 97 passengers and four crew crashed because the wind was too strong according to local reports which said they ran out of runway. the crash happened in durango, mexico. we've now learned multiple people are injured and two are in critical condition. aeromexico saying we are working to gather additional information and will provide more details as they become available and confirmed. our priority is to guarantee the safety of the clients and crew. lester, this just in, initial reports from the u.s. government say there were no americans on board and so far the mexican government has said there are no reported fatalities. >> tammy litner tonight, thank you. >>> let's turn to the latest threat, plastic weapons knockof. the technology is accessible and so are the guns. tonight, a federal judge has just blocked a release of blueprints for the guns after several states took legal action to stop their release. tom costello has late detail

tammy leitner, nbc news. >>> coming up tonit, was it excessive force? an 11-year-old tased for allegedly shoplifting. her outraged mother is speaking out. we'll have it. the first survivor of alzheimer's disease is out there. and the alzheimer's association is going to make it happen. but we won't get there thout you. join the fight with the alzheimer'association. we're alr one roof now.d. congratulations. thank you. how many kids?hi my two. s three. along with two dogs and jake, our new parrot. that is quite the family. quite a lot of colleges to pay for though. a lot of colleges. you get any financial advice? yeah, but i'm pretty sure it's the same plan they sold me before. well your situation's totally changed now. right, right. how 'bout a plan that works for 5 kids, 2 dogs and jake over here? that would be great. that would be great. that okay with you, jake? get a portfolio that works for you now and as your needs change from td ameritrade investment management. but climbing 58,070 steps a year can be hard on her feet, knees, and lower back. that'

tammy leitner joins us with the very latest. good morning. >> reporter: good morning, hoda. after two weeks of uncertainty, police now know who killed dr. mark hausknecht. its the man who lived in the house behind me but the big question this morning, where is he? police say this was a targeted killing by a man who held a grudge. this morning, a manhunt for a person who police say is armed, dangerous and suicidal. this morning a manhunt under way. houston police zeroing in on joseph james papas who they say is armed and dangerous. >> we believe that this absolutely is the killer. >> reporter: police say papas targeted shot and killed mark hausknecht in broad daylight nearly two weeks ago possibly seeking revenge. >> the suspect's mother was the patient of a doctor and died during surgery over 20 years ago. >> reporter: police suggest the 62-year-old combined that grudge with preparation. >> there's a lot of planning. the shots he took took some skill. >> reporter: an autopsy shows dr. hausknecht was shot in the head, torso and left arm. police say the case broke open after p