"Everyday there's more applications coming in on that fax machine or coming in our mail or being hand delivered," says Elena Russo, spokesperson for Maryland State Police.
Some gun store owners say the recent proposed legislation is to blame.
"Unfortunately, I think we're becoming a violent country. I think a lot of the negative politics are politics of fear," says Senator Ron Young (D), Frederick and Washington Coutny. "I'm voting for parents who can drop their kids off at school or take them to the movies and feel like they're safe."
But the increase in gun sales means more work conducting background checks for the Maryland State Police.
"In the months of December 2012 through January and February of this year, those three months combined we've received almost as many applications as we've received in all of 2008 and 2010," says Russo.
Officials say they're working 21-hour days to keep up but they're still six weeks behind.
"It's truly an unprecedented increase," says Russo. "We're averaging more than 425 applications a day."
So they've resorted to bringing in more help to try to speed up the process.
"We have about 60 qualified people that have been taken away from their computers to work on these background investigations," says Russo.
Officials say they don't want to sacrifice accuracy for speed.
For each application, officials have to check about 17 different databases.