single gunman commit the largest mass shooting in modern american mystery. and now it could be going back on the market. we'll break down the supreme court's decision to nix a federal ban on bump stocks. plus, ukraine already short on money, short on manpower, but is it also running out of time? vladimir putin just offered his own version of a peace deal with provisions president zelenskyy has already rejected, but how long can he hold out? first, some breaking news, nbc news has just learned the princess of wales, kate middleton will make her long-awaited first public appearance tomorrow, her first since christmas, and her first since revealing she is being treated for cancer. lest get right to nbc's meagan fitzgerald live at buckingham palace for us. this sounds like good news. what do we know about this appearance and how the princess is doing? >> reporter: yeah, ana, this is incredible news coming out of kensington palace just minutes ago. in fact, we know that the princess writing a handwritten letter herself along with a picture that was released. i want to read for you part of when she said. she said i'm making good progress, but as anyone going through chemotherapy will know, there are good days and bad days. my treatment is ongoing and will be for a few more months. on the days i feel well enough, it is a joy to engage with school life, spend personal time on the things that give me energy and positivity as well as starting to do a little work from home. now, look, anybody who has experienced cancer or knows someone who has, this is certainly a very personal and humanizing letter to the world. the good days and the bad days, when she has good days, she relishes in those moments. when she has bad days she surrenders to her body. she is trying to do what she can in terms of working from home. this is huge news, the fact that we are going to be seeing her tomorrow at trooping the colour, which is the king's official birthday celebration. highly anticipated. we know that sheiling in the carriage along with her three children, and we will see her for that highly anticipated balcony moment as well. you know, there was speculation around this because, as you remember, just last week she wrote a letter to her troops apologizing for not attending the rehearsal for trooping the colour, she of course is the colonel of her -- of the irish guard, something that she took over from her husband. there was speculation we may not see her tomorrow. but again, really incredible and encouraging news coming out of the palace saying that the princess is progressing well and all eyes, ana, will be on tomorrow's event where we will see the princess for the first time since she released that video three months ago saying she's undergoing preventative chemotherapy treatment. ana. >> so great to hear that the princess is making good progress in her words. back here at home to that major supreme court decision today striking down a trump administration era ban on bump stocks in a 6-3 decision. the court ruling that the ban on a device that allows semiautomatic rifles to fire at a speed rivaling that of a machine gun is unlawful. the bump stock ban was enacted in 2018, during the trump administration after the deadliest mass shooting in modern u.s. history when one shooter killed 60 people and injured hundreds of others at a las vegas country music festival. justice clarence thomas writing for the majority saying that a firearm equipped with a bump stock doesn't meet the definition of a machine gun under federal law. now, justice sonia sotomayor strongly disagreeing writing in her dissen sent, quote when i see a bird that walks like a duck, swims like a duck and quacks like a duck, i call that bird a duck. trump saying, quote, send me a bill and i will sign it immediately. joining us now, nbc's yamiche alcindor, and retired atf special agent in charge jim cavanaugh and civil rights attorney and former prosecutor charles coleman. what is the latest reaction we're getting to this ruling? >> well, what we're really hearing from is both sides of the political aisles here. republicans largely saying that they're going to respect or celebrate this decision and democrats saying this is a decision that really needs to be rectified by congress. so with that in mind, let's take a listen to what we've been hearing from capitol hill and the lawmakers there. >> it's a fantastic ruling, not surprising. i would expect it to be done. that's an indication of where we'll be on the pistol brace ban as well. i think it was a foolish mistake under both administrations. >> the supreme court has been on a rampage with respect to the ability of states and localities to pass reasonable gun safety measures. >> so there you have it, republicans and that republican lawmaker saying essentially i'm in favor of this ruling and then you have someone like jamie raskin, a high profile democrat saying he doesn't agree with this. i want to also read senate majority leader schumer's statement, he said as i warned the trump administration at the time the only way to permanently close this loophole is through legislation. senate democrats are ready to pass legislation to ban bump stocks, but we will need votes from senate republicans so there you have it. justice alito in his concurring opinion, which means that of course he agreed with the opinion in that 6-3 decision, justice alito was saying it has to be congress that would pass a law that would ban bump stocks. you have now senate majority leader schumer saying let's do that. we're going to need republicans on board. i want to remind people there's the presidential politics at play here. this was a 2018 ban on bump stocks that went into effect under donald trump. he was supportive of it at the time, so was the nra. the nra has backtracked. you have the trump campaign saying they're going to respect this decision but that they are still friends of the gun rights advocates community, but then you have someone like president biden and the biden campaign that are saying that this decision says that trump justices, that they are putting safety of communities behind the gun lobby. so very interesting here, that's sort of the reaction we're hearing on the political front, ana. >> yamiche, thanks so much for that reporting. the court says bump stocks don't fit the definition. saying quote, a bump stock does not alter the mechanics of a firing and the trigger must be released and reengaged to fire each additional shot. you know guns well, do you agree? >> no, i mean, the supreme court is dead wrong unfortunately for america, we're going to suffer the consequences. if you see someone fire a bump stock or have fired a bump stock, you pull the trigger back and hold that gun against your shoulder. you don't pull the trigger manually, and the 1934 firearms, national firearms act that regulated sub machine guns described a sub machine gun or machine gun as a weapon that fires more than one by a single function of the trigger. a bump stock turns a rifle into a sub machine gun. this is not even a legal question, oh, they're trying to say that the atf director doesn't have the administrative authority. they could have easily said in this case, look, if congress wants to ban the atf director's ruling says bump stocks are sub machine guns and if congress wants to make them legal, they can pass a law and do that. they could have easily said that, just the same administrative issue. congress can pass a rule and say bump stocks are illegal, but no, they allowed these things now to be out and i'm sure they're being manufactured as we speak, and we're going to see the market flooded with them. they're going to be on the street. they're going to kill our law enforcement officers. if you see a person fire these next to someone firing a sub machine gun, you can't tell the difference. it will put out 600 rounds a minute. a human being cannot pull the trigger that fast. that's why this mechanism turns the gun into a sub machine gun. you'd have to be the village idiot to say it's not. it's too clever by halfway to get by the law. the spirit of the law, the reason for the law in 1934 because of the gangsters, pretty boy floyd massacred the four law enforcement officers at the union train station in kansas city, the st. valentine's day massacre, all these, you know, bonnie and clyde killing policemen with a b.a.r. all these machine guns were ravaging america, and congress passed that law. and now we have this ruling trying to go on a legal technicality, which is nonsensical to try to tell you that it's not a sub machine gun t. is a sub machine gun. >> even many of the justices during oral arguments talked about the carnage and the intention of that machine gun ban was to limit the type of carnage and you just think about 60 people being killed with hundreds injured by one man who had this bump stock and these devices at the las vegas music festival, and by the way, when this bump stock ban initially was instituted just a few years ago, there were some 520 plus thousand of the bump stocks already circulating. charles, i'm wondering, could this ruling now sort of open the door to other challenges on other types of gun restrictions? what are the broader legal ramifications here? >> i would expect so, ana. i think that when you're looking at what this ruling signifies, it is an invitation, if you will, to a pro-second amendment folks to try and push as much as they can in the spaces that they are now questioning, and i think that the supreme court essentially punted for many of the reasons that jim already talked about. they could have directly addressed this issue. i understand legally why they took the route of saying that atf did not have the authority, if you will, to try and make these regulations, but they could have made it very clear, and it is very interesting that congress has already picked up on the notion that they've given them a pathway to fix this if you want to legislate. but what the supreme court has done with a decision like this, ana, is they've basically said, look, if you want to bring these cases, we're going to find a way to allow them to breathe, to give them breathing room, and that has dangerous implications if you're someone who is looking to have and pass and keep common sense gun legislation. >> and to save lives potentially. >> yes. >> this sort of a situation is all about saving lives. jim talking about federal versus state laws when it comes to gun rights. 18 states already have their own bump stock bans according to every town for gun safety. so what do you think atf enforcement will look like with these, you know, different state and federal regulations? >> it's going to be a scientific wild ass mess because you're going to have states that, you know, have them illegal and other manufacturers are going to be pumping these things out to make money, and you know, they can be trafficked across the state lines, but it's going to be a mess. it's unbelievable they would make that decision. really, if you shoot one of these things, you just can't believe that someone could not call it. my description, ana, is like a guy's in a boat, and he hangs four tires off the side, and the coast guard pulls up and says we want to inspect your boat. you can't inspect it because it's a car, it has four wheels. it's nonsense, it's nonsense, and it's really sad. i mean, i can't believe -- the other part of the argument, and of course charles can go deeper than me, i'm sure, but when they argue about the administrative state, again, that's a silly argument as well. look, the atf has to decide on all kinds of devices. i don't know the number exactly but scores and hundreds during the year. is this thing a silencer? is this thing a firearm? does this thing change a firearm? they're sent in by the bucket loads. are they saying that atf can't make those decisions? that everyone has to go to the supreme court? i mean, it doesn't make any sense. cops make decisions administratively every day. is this careless driving, is this reckless driving, you know. you have to make a decision based on the law. you can't call the judge and say, well, is it? you have to decide, and the atf director did, and he made the right decision and the supreme court is just dead wrong. >> charles, what do you think of justice sotomayor's dissent where she says of the decision, quote, this majority opinion casts aside congress's definition of machine gun and seizes upon one that is inconsistent with the ordinary meaning of the statutory text, and unsupported by context or purpose. >> i think that when you're trying to get to a particular conclusion that does not jive with your facts, you have to go around and say things that are nonsensical, and justice sotomayor is pointing that out. she's basically saying there's a common sense definition that has support in the law for what a machine gun is. and in order to reach this decision, in order to actually punt in the way that the majority has decided to, you had to go around that common sense definition, and she's pointing it out. she's pointing out something else, though, i think that is important, which is congress's ability to fix all of this through legislation basically saying that, look, you have found the most egregious and obscure way of looking at the interpretation of statutorily at least machine guns, but you can fix it if you basically change the definition or be more specific. the problem with that, ana, is that to jim's point, how many times are you going to have to do this with how many different accessories and attachments that weapons can have such that we don't constantly find ourselves here again and again where congress has to redefine every single attachment, a scope, a silencer, a bump stock that can be applied to a weapon to change how it functions. that's a real issue that that dissent actually points out in a subtle way. >> i think you touched on this, jim, just how concerned are you that there could now be a rapid boom to the rapid fire marketplace, now that this ban is gone, what does this mean for public safety? >> no, it's a bad day. it's a bad day at black rock here because these manufacturers are going to be pumping these things out now to make money and to make millions of dollars. there's the video that proves the supreme court's decision is wrong. you see that shooter. he's holding the trigger. he's not pulling the trigger with his finger manually. he's not moving his finger back and forth. he's just holding it against his shoulder, and it's firing the gun. they will have great lawyers like charles on there who can explain to us the supreme court and all these things, but i'm telling you this decision isn't a legal one. it's a wrong one because if you just look at the way the gun works, there's only one pull of the trigger and it's held back against your shoulder and it empties the magazine, and so they just made a wrong ruling for america, and it's going to kill and hurt a lot of people. >> i appreciate your expertise, your passion, jim cavanaugh, charles coleman and yamiche alcindor, thank you all so much. in 90 seconds, president biden showing solidarity with ukraine at the g-7 as putin lays outs new conditions for peace talks. looking at live pictures. this is in italy. we'll have what's behind the strategy and the timing of all of this next. and the timing ofl of this next power e*trade's award-winning trading app makes trading easier. with its customizable options chain, easy-to-use tools and paper trading to help sharpen your skills, you can stay on top of the market from wherever you are. e*trade from morgan stanley power e*trade's easy to-use tools make complex trading less complicated. custom scans can help you find new trading opportunities, while an earnings tool helps you plan your trades and stay on top of the market. e*trade from morgan stanley ♪ you need t-mobile... ♪ ♪ home internet with 5g. ♪ wait! t-mobile has home internet? ♪ what a feeling! ♪ ♪ to have t-mobile now! ♪ we're still going for that nice catch. we're still going for that perfect pizza. and with higher stroke risk from afib not caused by a heart valve problem,... ...we're going for a better treatment than warfarin. eliquis. eliquis reduces stroke risk. and has less major bleeding. over 97% of eliquis patients did not experience a stroke. don't stop taking eliquis without talking to your doctor as this may increase your risk of stroke. eliquis can cause serious and in rare cases fatal bleeding. don't take eliquis if you have an artificial heart valve or abnormal bleeding. while taking, you may bruise more easily... ...or take longer for bleeding to stop. get help right away for unexpected bleeding or unusual bruising. it may increase your bleeding risk if you take certain medicines. tell your doctor about all planned medical or dental procedures. the number one cardiologist-prescribed blood thinner. ask your doctor about eliquis. live pictures from italy to show you where president biden is meeting with world leaders. they're discussing the race against time for ukraine with new questions about whether international pledges of support can do enough and last long muff to help them win the war with russia. and that includes that ten-year security agreement president biden signed yesterday, one without guaranteed aid. that may last only as long as he is in office. nato responding today by agreeing to take over part of the u.s.'s role in coordinating support, and "politico" says it's widely seen as an attempt to trump proof the effort in case president biden loses in the fall. meantime, russian president vladimir putin is making moves of his own offering peace talks but only in exchange for ukrainian territory, something president zelenskyy says is off the table. all of this amounting to a faceoff between putin and the west as the clock keeps ticking. and as "the new york times" writes, quote, for the first two years of the war, it was assumed time was on ukraine's side, that mr. putin would have to back down if the war stretched on too long. now no one is sure that is still the case. i want to bring in monica alba who is traveling with the president in italy. richard engel is nbc's chief foreign correspondent, he's inside ukraine, and peter baker is "new york times" chief white house correspondent and an msnbc analyst. monica, we heard president biden say putin can't wait us out. behind the scenes, just how concerned is the white house about ukraine's ability to keep up this fight without getting more help from congress and other countries? >> reporter: well, certainly, ana, during that battle on capitol hill that we saw play out over the last many months, it was unclear whether additional funding was going to be approved for ukraine. there was a lot of concern and anxiety in the white house and in the biden administration overall about what kind of message that would send to president putin and to ukraine's desires to continue its defense against that russian aggression. but once that was approved and those weapons and air defense capabilities started to roll out, there was a feeling that they could try once more to try to rally the international community around this. but, there was also this sense that this may be the last best opportunity to do so because you look domestically for the president at what americans feel in terms of continuing to support this effort and many simply don't feel that they can be convinced that their taxpayer dollars should be going there anymore. that is why he does need to turn to some of these other countries and leaders to try to bolster this. of course the fact that they have this now decade long commitment and agreement tells you everything that the president wants to be able to say here at a summit like this one in southern italy, which is