>>3348081An argument (In computer science) is a new piece of information that changes the outcome. But if none of the above works, then I'm afraid your going to have to take some EXTREME and very dangerous measures. If you willing to risk going to prison, then you can hire a black gang to kill her boyfriend. I don't have any personal experience when dealing with black gangs, but I'd say about $4,000 USD would be enough. Of course, don't take all the money with you when you go to meet them. Put about $1,000 in a wallet and give them the whole thing (Make sure there are no fingerprints or markings that would tie the wallet with you or the receipt/store that you bought it from). This is so they don't rob you. Don't have any valuables on your person and get right to the matter at hand.
Before this, gather as much Intel on her boyfriend as possible, without seeming suspicious. Walking & driving routes (parking spaces?), photos of the clothes he wears, shoes, car, house, where he hangs out, when he arrives or leaves, ect. Make sure that the photos you give them, won't be recognized as ones that you took. Like, if you take a photo of them together, she'll be able to recognize it as one that you took. Now, this goes without saying, but give them specific instructions to not hurt your sister. When meeting them for the first time, you should wear a mask and clothes that don't show that your white. As for payment, the rest of the money $3,000 will be made at a "Dead-Drop" (Dead Letter Box), which is when two or more individuals can drop items or info in a location where neither have to meet face-to-face. Get their phone number and call them using a pre-paid disposable phone. Tell them where to go after the job is done and watch them from afar using binoculars. Place the money in a hiding place and tell them where to pick it up.
Do you see any flaws?