A disgruntled former nursing student of Oikos University walked into classrooms yesterday and shot seven people who were attending class, officials say. He also wounded three others.

Oakland police used Twitter to broadcast a description of Goh before apprehending him at a local grocery store, where he turned himself in not long after the shootings:

And again to alert nearby residents that he had been taken into custody:

43-year old One Goh told police that he was upset about being dismissed from the university, which is a Christian medical school. Police had a hard time discerning a motive at first, as when they took Goh into custody they had to wait to find a Korean translator.

Witnesses in the school say Goh walked in, shot the receptionist, and headed for the classrooms, apparently looking for a specific female administrator who Goh blamed for his dismissal. Early reports state that he lined up the victims against the wall in one room and shot them execution style.

“This was a calculated, cold-blooded execution,” Oakland Police Chief Howard Jordan told CNN. Charges are expected to be filed tomorrow.

Oikos, a small private school in Oakland, CA, only has about 100 students currently enrolled. The tragic loss of so many will undoubtedly weigh heavy on those left to pick up the pieces this week.