Based on the Locard Exchange Principle, how might the forensic technician connect the shooter to both crime scenes?

Case StudyThe Virginia Tech Massacre In two separate incidents approximately 2 hours apart, one of the deadliest single-perpetrator shooting rampage in the history of the United States occurred at Virginia Polytechnic Institute and State University (Virginia Tech) in Blacksburg, Virginia, on April 16, 2007. The shooter, Cho Seung Hui, killed 32 students and faculty and wounded 30 others before committing suicide. Beginning shortly after 7:00 a.m. at West Ambler Johnson Hall, a dormitory on the Virginia Tech campus. Cho used two handguns to kill and wound his victims. The early morning events are summarized as follows:7:15 a.m. Police receive a 911 phone call, reporting shots fired at Johnson Hall. Police find a female student and make resident advisor fatally wounded. Based on witness interviews, police believe the shooting is an isolated domestic incident. Police do not initiate campus-wide security measures. Police focus on the female victim’s boyfriend, a student at nearby Radford University. Police later stop and interrogate the boyfriend on a highway in Blacksburg.9:01 a.m. At a nearby post office, Cho mailed a package containing writings and video recordings to NBC News. Cho linked himself to Jesus Christ and expressed hatred for wealthy people.9:26 a.m. Virginia Tech authorities issue first mass email, reporting the 7:15 a.m. shooting and warning students and staff.9:45 a.m. Police receive a phone call about a shooting at Norris Hall, a science and engineering classroom building, about 15 minutes walking distance from Johnson Hall. After Cho chained the Norris Hall exterior doors shut, he killed 30 students and faculty in their classrooms before killing himself.9:50 a.m. A second mass email by Virgina Tech officials reports a gunman is loose on the campus.9:55 a.m. A third mass email reports the shooting at Norris Hall and the gunman is in custody.Subsequent to the mass killing, it was learned that Cho was treated previously for mental illness.Were any or all of the killings at Virginia Tech preventable? Why? Explain.The VA Tech incident involved two crime scenes. Based on the Locard Exchange Principle, how might the forensic technician connect the shooter to both crime scenes?