So I'm trying to work something out with my story. Does anyone know what would happen to someone if they were injected with heroin but missed the vein? I've done some google searches and found small pieces of information, like how it would still take effect but would take longer and the injection site could become irritated, but I'm trying to figure out more specifics. I have a character that needs to die and have it look like an accidental overdose. I tried to look up ways to get him knocked out so the protagonist could safely set him up and find the vein and all that, but I cant figure out a way to knock him out without the drug used to put him to sleep showing up on a toxicology report. So if you have any ideas on that, that would also be helpful. So for now I just have the protagonist stabbing him with a needle of heroin, but I don't know how effective this would be in killing him. I figured (if it did kill him) she could set him up after he is dead and make it look like he injected himself and missed the vein, but again, not sure how realistic this is. Any opinions?