Billy knows there's too much publicity to get Velma off on a jury trial, so he asks Mama to find someone. He sets Roxie up as the 'sweetest little jazz killer', Velma vanishes from the papers; Billy can cut a plea-bargain for his original client. He really is the best lawyer.
It gets better — in the process, he convinces the jury (and possibly the press) that the assistant district attorney tampered with evidence to frame Roxie. Not only did he get ten grand off of Roxie and Velma while keeping his perfect win record, he used them to eliminate a powerful rival.
The opening number "And All That Jazz" seems like a really cool opening number. Then you notice one of Velma's line "I'm no one's wife but, oh I love my life" seems just like a cool, feminist thing to say... until you realize she has just murdered her husband.
Reading Hunyak's translation from the Hungarian, she says that she doesn't know why she's in prison, and mentions her "famous lover." What if her lover's fame is what got her case attention in the first place — in this case, attention that led to her unjust execution? It would make her story a dark and complete inversion of Roxie's quest to find fame via murder.
In the cut song "Class", Velma and Mama are complaining that there are no decent people left. Well, there is at least one: long-suffering, faithful, selfless Amos Hart. One of the lines in that song is "there ain't no gentleman that's fit for any use." And in the introduction to "Roxie", Roxie explains that she cheated on him because he was no good in bed—as in, not fit for any use.
Also a callback to "Mr. Cellophane." Amos is the closest thing to a decent person the film has...but they forgot he existed.
The Hunyak is played by a Russian actress, and even Hungarians have trouble understanding her bit in Cell Block Tango. It's a double Language Barrier - her own people can't understand her clearly, so how can the cops?
Amosdoesn't! Though as a lowly mechanic who'd saved up enough to shower affection on his undeserving wife, his quality of life probably wouldn't change too badly. And with Roxie out of his life, maybe he could find a good woman deserving of his time.
Besides, if he's smart, he can sell off all of Roxie's mementos, leaving him better off than he was when the play started (if by no other reasoning than "he's free of Roxie for good.").
Big if. Amos is many things, but smart isn't one of them.
In a darker note, it's hard to imagine those two big egos sharing the spotlight for very long. Both of them spent their entire time in prison resenting one another. And both of them have killed before.
Throughout the film, we see musical numbers taking place on an imaginary stage in the characters' minds. At the end of the film, Velma and Roxie perform a wildly successful show to an adoring audience. But... Is that their real performance at all? Or is it their imaginations?...
Compare Roxie's singing in the last musical number to her singing for her audition (after the imaginary sequence). Big difference, hm?
Even if you look at the difference between "Nowadays" and the "Hot Honey Rag" sequence (which appear ...In That Order in the musical), the difference is very pronounced.
Personally, I always took it as real. The fantasy sequences are always made apparent within the movie if they are fantasies, and the last one seems to be very real, similar in style to "All That Jazz"- full audience, no surreal effects like having the performers completely isolated onstage or the scene just not making sense. Plus this troper just plain likes it better as a better ending, as it shows just how blind we as the public is willing to be sometimes to the reality of a celebrity's actions as long as they're still entertaining.
Some credence to this: in the 'mind theatre' segments, we only see audience members as shadowy figures such as in "All I Care About (is love)" but during "Nowadays", and "Hot Honey Rag", the audience is as clear as life. vanishing gun stands aside, it seems much more real than the other numbers post "All That Jazz"
As bad as Roxie and Velma are, it's worth remembering that Morton, Flynn, and the press are all shown to be utterly indifferent to their guilt. Profit and publicity are what matters, and mere moments pass between Roxie's verdict and the next killer going celebrity.
Anne says that the polygamist she poisoned was a Mormon, hence all the wives. Yet she also says she poisoned him by putting arsenic in his "drink" (implied to be alcoholic, so as to mask the taste). Except...Mormons aren't supposed to drink alcohol. Considering that it's only Mormon fundamentalist sects that practice polygamy, it seems a bit strange he would break that particular rule and be devout about everything else.
Maybe he was using his Mormonism as an excuse to have as many women as he wanted whilst ignoring the parts he didn't like?
Mormons also aren't supposed to commit adultery, but he was doing that as well. He was clearly not a very good Mormon.
You could read the line about him being Mormon as not meant to be taken literally; basically, the guy was seeing several women at the same time, so she called him a Mormon (a religion known for polygamy, at least in the past) as a sarcastic way of saying he was promiscuous.
Or, she's not being sarcastic, and just literally knows nothing else about Mormonism, and so assumed "Polygamy=Mormon."
Anne gives her late lover's name as Ezekiel Smith—deeply Biblical first name, surname of the founder of the Mormon faith—and says he's from Salt Lake City, a city founded by Mormons and a center of the Mormon faith. The implication seems to be that he was actually a Mormon.
Good luck finding ANY religious sect where every single member is 100% faithful to every single rule.
It's actually quite likely he really did like his drink. The Mormon prohibition against alcohol didn't become mandatory until 1921, when Prohibition really hit the US. Before then, it was mostly a suggestion, and even to this day, adherence varies by location.