Well, first of all, my bill for legal advice is in the mail to ya. I do take 5.56 ammo in payment.
Second, will depend of what the charges ARE. If he has been indicted for a crime that is a felony, OR is a crime of domestic violence, then NO. That is not MD, but Federal- applies everywhere, and is one of the questions on the 4473.
The federal standard is under indictment, if he hasn't been indicted, he won't run afoul of federal law.
There are still some Maryland hurdles he may have to jump through. He was arrested and released on recognizance or bail, a Maryland court commissioner or judge may make his release conditional, including a condition that he turn in firearms, failure to do so could lead to re-arrest and confinement before trial. Even if it isn't specifically noted, obtaining a new firearm under this condition would have the same result.
There are some next steps to consider, best case, your friend did nothing wrong and the charges would be dropped or he'd be acquitted, he could plea to a lesser charge, or he could be found guilty. If he plans to plea, he'll have a hard time ever owning a gun again if the charge could carry a sentence of more than one year, the same if he's found guilty of assault in Maryland. Even if he pleads guilty to a charge with a potential sentence of one year or less, he still may get probation, which may include a condition prohibiting the position of firearms. Even if there is no specific condition prohibiting it, probation officers in Maryland have such discretion.