More people have been murdered and shot in Prince George's County this year than last year -- and the county executive says many of the guns used come from out of state.
Prince George's County Executive Rushern Baker is calling on other states to adopt gun licensing laws like those in Maryland.
"One of the things that we suffer from is our surrounding neighbors don't have the same type of [gun] restrictions that we have," he said.
The number of homicides in the county this year rose 53 percent compared with the same period last year. The number of non-fatal shootings rose 14 percent. Many of the guns used were bought legally in other states.
"In domestic violence and some of the homicides that are committed, they're committed with guns that were purchased legally somewhere else but brought illegally into Prince George's County, into the state of Maryland," Baker said.
The man suspected of opening fire on police officers last month in Palmer Park used a .40-caliber gun purchased in 2009 in Georgia, police said. The gun was bought legally and passed around suspect Michael Ford's family for years. It ended up in Ford's hands some seven years after its original purchase.
The group Marylanders to Prevent Gun Violence says 44 percent of guns used in crimes in the state come from other states.
Maryland Attorney General Brian Frosh said what Maryland is doing is working and other states should do the same.
"It has already reduced gun deaths in Maryland," he said.
A majority of voters, 59 percent, surveyed in the NBC4/Marist Maryland Poll conducted this month said they wanted laws covering the sale of guns to be more strict. Twenty-four percent of voters said to keep gun laws as they are now, and 14 percent said the laws should be less strict. Just 3 percent of voters were not sure.