When Coral Springs police officers arrived at Marjory Stoneman Douglas High School in Parkland, FL, on Valentine’s Day, they saw not just the officer assigned to the school but three more Broward police officers with pistols drawn but taking cover behind their cars as a gunman was inside killing 17 students and staff, CNN’s Jake Tapper reported Friday, citing sources.

When those Coral Springs police entered the building, the four original Broward officers on scene did not join them, sources told CNN. It’s unclear whether the shooter was still in the building when they arrived.

One day earlier, Broward County Sheriff Scott Israel held a press conference at which he acknowledged the armed deputy on duty at Stoneman Douglas High never entered the building where last week’s slayings were occurring.