This is a good question because a lot of federal criminal cases, multiple defendants are charged at the same time, and usually what you'll see is whoever's at the top of the indictment in a federal criminal case, is usually who the prosecutors or government view as the most serious players in the criminal case. In other words, those who are most involved are facing the most time in a criminal case.
So, a lot of times you want to see what one defendant will get, and if you're similar to that defendant, you can make an argument that your sentence should be the same or even better, depending on how you compare to that particular defendant. So, that is a very good argument.
Disparity in Sentences
It's essentially argued that there shouldn't be a disparity in sentences for defendants who are similarly situated. For example, let's say in a drug trafficking that, multiple people are moving drugs from point A to point B. They're getting paid $1,500.00 every time they move the drugs.

It doesn't matter what kind of drugs they are. It doesn't matter how many drugs there are. It doesn't matter the value of the drugs. All these people are basically mules in the drug scheme. So, if you catch two or three mules doing the same thing, moving the same drugs, they should all receive the same sentence, unless they have a prior criminal record or some other distinguishing factor.
Suppose they're similarly situated, meaning they share similar circumstances and are equally culpable. In that case, there's a good argument that if you're the second defendant to get sentenced after someone who is similarly situated to you, that you should get at least the same sentence as them, maybe less, depending on whether you have a criminal history or they have a criminal history. There are several other factors that will be taken into account.
Comparing defendants in federal criminal cases is something judges will do, and it's also something a savvy defense attorney can bring up at a federal criminal sentencing to point out to the judge that perhaps one particular defendant received no custody time in a case.
As a defense attorney, you have the power to influence the fairness of your client's sentence. If your client is similarly situated to a co-defendant who received no custody time, you can make a compelling argument that your client shouldn't receive any time either. This is about advocating for fairness and questioning why one defendant in the same position as another should receive a different, harsher punishment. Your role is crucial in ensuring that the judge considers all relevant factors in the sentencing decision.
Downward Departure in Federal Sentencing
So, this is definitely a factor that can be argued to persuade the judge to depart downward, particularly if you fall into a category where you're looking at five to seven years in federal prison, but a co-defendant who is similarly situated to you in all respects received a three-year sentence.
You would certainly have in your position paper an argument that there shouldn't be a disparity in sentences and that you shouldn't get any more time than that three years that the co-defendant got, even though your criminal history and your guideline range puts you at a higher level, that the judge should compare you with that other co-defendant and give you the same or less sentence.
So, this is just another tool in your federal criminal defense toolbox as an attorney to thoroughly examine all the angles. If you've got some defendants who sit in the same position that your client sits, you want to consider making that argument, again, depending on what the sentence is.
That's why sometimes in a federal criminal case it's nice to be the second, third or fourth person sentenced versus being one of the first people sentenced, because that tends to bite into your argument that you should get the same as somebody else, because obviously that person hasn't been sentenced yet, you're not going to be in a position to get the same sentence as them. This is another factor to consider when reviewing federal cases.
If you've got a federal criminal defense case and you're looking to getting a lower sentence because you have to take a deal on the case because the government has the goods on you, you're going to need to get an attorney who can look at every single downward departure and do the best they can to get you the best result.