Police said cameras located in the common area and exits of the dorm captured Davis leaving the dorm, heading north and running along train tracks.
The shooting led authorities to order a lockdown of the campus, which has more than 20,000 students, and police also warned Mount Pleasant residents to be on guard.
As nightfall came and 12 hours had passed in a fatal double shooting on the Central Michigan University campus, the suspected gunman was still "at large".
State police now say Davis Jr. may have used his father James Davis Sr.'s own gun against his parents.
Friends and teachers who knew the suspect personally, said they could not imagine he was capable of such a crime. There are no other injuries reported.
There are no details at this time of where or how Davis was arrested, but according to the city of Mount Pleasant Twitter account, he was taken into custody without incident.
The Davises were reportedly picking up their son from his college campus for spring break when the shooting happened.
Davis is from Plainfield, Ill., a suburban community south of Chicago.
He was sought in connection with the shooting deaths of, who were later learned to be, his parents, James Eric Davis, Sr., and Diva Jeneen Davis, both 47 years old, early in the morning at Campbell Hall in The Towers complex on campus.
Parents trying to pick up students at the school were being asked to stay off campus. "This has been a tragic day for Central Michigan University", said CMU President George Ross. An automated phone message was sent to students.
One student said she locked herself in her off-campus house, which is about a 10-minute walk from the residence hall.
Students and staff in the Mount Pleasant school district were told not to leave several buildings.
Parents hoping to collect their children for spring break were told to go to a local hotel instead. She had planned to run errands before traveling home to the Detroit area. Visitors also weren't being allowed to enter.
The university's statement Friday evening said all campus events were being cancelled until further notice.