(CNN) -- A Pennsylvania wildlife officer investigating possible poaching was killed during an exchange of gunfire after making a traffic stop late Thursday, authorities said.
David L. Grove, 31, was fatally shot in Freedom Township near Gettysburg, according to State Police Commissioner Col. Frank Pawlowski.
Authorities detained Christopher Lynn Johnson, 27, early Friday, and were in the processing of bringing charges against him in the case, according to Adams County District Attorney Shawn Wagner.
Johnson sustained a gunshot wound and was receiving treatment at a nearby hospital, Pawlowski said.
"It is truly a painful day for the Pennsylvania Game Commission," said department spokesman Jerry Feaser.
Grove was a "bright, highly educated conservation officer" who graduated from Pennsylvania State University with a degree in wildlife and fisheries science, he said.
Grove is the first the game commission officer to be killed in the line of duty since 1915, and only the third since the game commission was founded in 1895.