I think the murder of the working girl in order to get Geary on the side of the family is sort of glossed over. I believe the purpose of the scene was to show the family getting something over the senator at any cost. The cold-blooded murder of her shows just how ruthless and cold-hearted the family especially Mike. They had no regard for the girl. All they were concerned with was comprising Geary. I think many people were sort of misjudging the Corleone family as not really being all that bad. In fact, some might even have been enamored with the family. The films start off with the family members dressed in tuxes, or silk suits and hosting gala events. They "come out to this clean country in your oily hair -- dressed up in those silk suits - and try to pass yourselves off as decent Americans."

No doubt: Michael was a reprehensible character. A working girl was killed in bed with Tattaglia at the end of GF, but you might say she was "collateral damage." But, the girl in the brothel was a deliberately chosen victim i the plot to compromise Geary. And, Tom's description of her: "This girl...nobody knows she worked here...she had no family...it'll be as if she never existed."

I would say everyone is a reprehensible character varying only in accordance to their horrendous acts

The Geary, innocent working girl murder in which Tom himself played a big part, was beyond evil indeed
All just to get Geary in the Corleones pocket that the girl's life was worthless “as if she never existed” the cruellest of them all

The women were culpable too
Both Carmela and Kay knew what their husbands' business was, knew their rich, privileged life was funded by tainted money from other people's murder, misery and blood

Kay enjoyed the spoils of the blood money for more than 7 odd year until her bedroom was machine gun sprayed when it suddenly dawned! on her, this unholy and evil Sicilian thing that's been going on for 2,000 years must all end

Absolutely. It’s a brutal scene but I think the purpose is to show how ruthless the mafia really is. As great as the first Godfather film was it certainly romanticized it to the point that fans were cheering for the Corleones since we follow their story. But Part 2 was certainly darker and showed the true ugliness of that life.

I hor have a little different take on the scene. Senator Geary while not being, as far as we know, a murderer. But in his own way was just as slimy and despicable as the Corleones. The difference was their different demeanors. It was very apparent at his meeting with Mike in Mikes's study. He personified the definition of a slimeball, while Mike remained calm, cool, and collective. In the old days of movie watching the audience would have booed and hissed whenever Geary was on screen. I think we the audience were glad to see how defenseless and scared Geary was in the brothel. And putting aside the circumstances. It basically was the same with all the Corleones hits. Same with the hit on McClusky. The hits were mainly on individuals of low moral standing.

You hit the nail on the head. I always found it interesting that women that were "Married to the Mob", went on their way in life as if their husbands were very successful linoleum salesman.

Sure thing johnny ola Also the families who marry their daughters off to Mob men – status quo? deemed a good catch? Rich widow?!
1. Sandra – Sonny's wife
2. Teresa – Tom's [not in the muscle-end] wife
3. Apollonia – in spite of Michael being an American fugitive hiding in Sicily

Put Geary Aside. The fact they murdered an innocent girl is just downright evil. It dies t matter if she was a prostitute. Even Tom said “She has family she is easily disposable”. So the fact that they got rid of her like nothing makes it even more chilling

They knew Tattaglia was with working girl Killed her with him

Interestingly, it's a departure from the book: no machine guns, Tattaglia is standing by the bed and takes four shots to the belly.