CENTENNIAL, Colo. — Arapahoe High School students are preparing to go back to class this week, just over three weeks after a student opened fire inside the school.

In order to prepare for the students, faculty and staff were the process of reporting back to school on Monday.

This will be the second time faculty and staff members have returned to school since the Dec. 13 shooting, which left 17-year-old Claire Davis dead. The shooter, Karl Pierson, 18, also died in the attack, committing suicide.

Davis memorial service was held on New Year’s Day at the National Western Stock Show Complex.

On Tuesday, students will return to their classrooms to take the final exams they were supposed to take during the now-concluded first semester. However, school principal Natalie Pramenko said those final exams will be optional for students, not required, and will for grade improvement and nothing else.

On Friday, the school will hold a healing assembly for the entire school. After the assembly, the school will begin the second semester.

Students, faculty and staff were allowed back into the school days after the shooting to gather belongings. They have not been back in the school since then.

When students arrive back at school, they’ll see an increased police presence and an increase in available counseling, Pramenko said. A counseling center will be open at the Santa Fe House on 6509 South Santa Fe Drive nearby in Littleton to handle any overflow in counseling needs from 10 a.m. to 7 p.m. this week.