They fired hundreds of bullets and emptied dozens of magazines.
They practiced drawing different .40-caliber Beretta, Glock, and Sig Sauer handguns, seeing how each felt in a holster and how quickly an officer could get it out during a gunfight.
State firearm instructors even dismantled the guns, making sure troopers would be able to keep them clean and in good working order.
And now after weeks and months of testing, state police have started equipping their troopers with new Beretta Px4 Storm .40-caliber semi-automatic handguns.
"After rigorous testing by Maryland State Police experts, the Storm has proven that its simplistic design, safety features ... and overall dependability make it the firearm ideally suited for use by Maryland state troopers as they continue to serve and protect the people of our state," Colonel Terrence B. Sheridan, Superintendent of the Maryland State Police, said in a prepared statement.
The 1,650 new double-action Storms, which are manufactured in Accokeek, Prince George's County, will replace 11-year-old Beretta 96D .40-caliber semi-automatic handguns.
And because of a deal worked out with Beretta, the new guns will not cost the state anything. Greg Shipley, a state police spokesman, said Beretta is letting them exchange their old 96Ds for the new Storms.
City, county and state police officers all carry different guns, with bosses at each department saying they are happy with their sidearms.
And while county police have carried .40-caliber Sig Sauer P229 handguns for about a decade now, and city police officers have carried 9mm Beretta 92F handguns for even longer, neither department has any plans to upgrade.
"Basically, a gun is a gun," said Cpl. Tom Powell, a firearm instructor at the county Police Department Training Academy in Davidsonville. He stressed that officers inspect their guns every month, have them professionally inspected every year, and have them fully dismantled and rebuilt every three years to make sure they will work in the field.
"There are very rarely any problems," he said.
Hal Goldstein, owner of The Armory in Parole, said each gun has its advantages and disadvantages, though.
He said the Beretta Storms are made of a polymer frame that makes them lighter than the county and city guns, which are all metal.
That said, Mr. Goldstein said he likes the metal frames because he knows how they will hold up - pointing to a couple of Colt 1911s that are more than 80 years old, and displayed in a nearby case.
According to Beretta, the Storm features a spurless hammer, a rotating barrel and a special photo-sensitive coating that makes the gun glow in the dark.