SAN BERNARDINO (CBSLA.com) — A new report from the Justice Department and the Police Foundation reveal many new, disturbing and dramatic details about the San Bernardino terror attack last December.

The report revealed that three mystery people tried to rush the two terrorists – but these heroes were gunned down. KCAL9’s Tom Wait says the report also included new information about the bravery and heroism from police and paramedics.

The report focused on what happened the day Syed Farook and his wife Tashfeen Malik walked into the Inland Regional Center and started shooting.

When police and federal agents arrived on scene this is what they saw as they tried to clear the building.

“It was the worst thing imaginable—some people were quiet, hiding, others were screaming or dying, grabbing at your legs because they wanted us to get them out, but our job at the moment was to keep going,” the patrol officer said. “That was the hardest part, stepping over them.”

And there were more heartbreaking stories from victims.

A woman who was shot in the head asked a wounded coworker to call her mother to say goodbye. The coworker tried to comfort her and asked if she was okay. “The victim said I’m not, I’m bleeding from the mouth and then she closed her eyes for good,” the coworker wrote.

The shooting unfolded during a training session – a photo was snapped just minutes before the shooters fired more than 100 rounds.

“As the chaos unfolded, a round hit a fire sprinkler pipe causing water to pour out of the ceiling. The water and smoke that filled the room made it difficult for people to see. The shooters walked between tables. If someone moved or made a sound, the shooters fired one or multiple shots into their body,” the report related.

The terror couple escaped after they carried out their horrific crime. But an interview with a very observant witness helped police figure out who the masked shooters were — using body language and body structure. Witnesses also described the rented black SUV driven by the two.

A San Bernardino investigator quickly zeroed in on the rental company and officers made their way to the couple’s Redlands apartment and the chase began.

When it was over Farook was shot 26 times – his wife 15 times.

One other very troubling detail: Police found a bag in the conference room that contained three pipe bombs. They didn’t realize the bag was there until about six hours after the shooting. Police believe those explosives were supposed to go off after first-responders reached the scene.