Evans and Koroma, both starters, have been suspended for two games and are likely to miss the 3-0 Nittany Lions' game with Temple on Saturday.
If convicted, the maximum sentence would be 30 days' imprisonment and a $500 fine, according to Centre County District Attorney Michael Madeira. For those without prior convictions, the typical resolution is probation or participation in the Accelerated Rehabilitative Disposition Program.
"We're going to handle this like we would any other case," Madeira said.
On the evening of Sept. 2, police were called to the players' campus residence after a complaint of loud music. The odor of burning marijuana was detected, police said, and a search warrant obtained.
Police said they found a small amount of marijuana - estimated by Capt. Bill Moerschbacher at less than two grams - in the bedrooms of Evans and Koroma.
A "burnt roach containing marijuana" was found in Koroma's room, and "three small clear baggies containing marijuana" and a "burnt roach containing marijuana" were found in the room of Evans, according to court papers.
Two days later, Paterno announced that the players were suspended for the Sept. 6 Oregon State game.
University spokeswoman Lisa Powers said the Office of Judicial Affairs would carry out its own investigation before deciding whether the students violated the school's code of conduct.
"Because the charges do not involve an act of violence, there is no immediate change in their status as students," Powers said.
Powers said she could not estimate when the office would conclude its probe. If the players are suspended by the university, "they are suspended from all activities and cannot use facilities," according to the office's bylaws.
The latest accusations increase the number of Nittany Lions players charged with criminal counts since 2002. In July, an ESPN Outside the Lines report revealed that 46 Lions had been charged with 163 counts, with 27 having been convicted of 45 crimes.
Madeira said a two-week investigation was necessary because the suspects were public figures.
"In a case like this, you don't want to make it look like you rushed to file charges," he said. "And you have to take your time and make sure that witnesses want to come in and get interviewed."
Evans, a junior from Brooklyn, N.Y., and Koroma, a redshirt sophomore from Hershey, Pa., had not been charged with previous crimes. Evans recorded 121/2 sacks and was a first-team all-Big Ten end last season. Koroma started at tackle in last season's Alamo Bowl.
Aaron Maybin has filled in for Evans and Jared Odrick for Koroma. The defensive line has been besieged by suspensions, dismissals and injuries.
Tackles Chris Baker and Phil Taylor were kicked off the team in July. Tackle Devon Still and end Jerome Hayes have suffered injuries since the preseason.
"It's like every week we get another guy banged up on that defensive line," Paterno said Tuesday.
"We lost five, six kids, people who could play against anybody we're going to play against this year," he said. "But the ones that are left are fighting like dogs to get to be good enough."
The rest of the team said it could continue to succeed without Evans and Koroma.
"I think we proved that last week and the week before," safety Anthony Scirrotto said.
Contact staff writer Jeff McLane at 215-854-4745 or firstname.lastname@example.org.