D.C. Police Chief Cathy L. Lanier revealed Tuesday that a second police officer was struck by bullets in last week’s shootout with the gunman who killed 12 people at the Washington Navy Yard. The officer’s protective vest stopped the rounds, she said.

Authorities had previously said that Officer Scott Williams, a 23-year veteran who lives in Calvert County, was shot in the legs. He remains at MedStar Washington Hospital Center, although Lanier said she hopes he will be released this week.

The chief, during her monthly appearance on NewsChannel 8’s “NewsTalk,” said that a second officer “actually took two rounds to the chest.” She said he was hit during a “confrontation with the gunman. We are extremely lucky we didn’t lose a police officer in there as well.” Lanier did not say whether the officer was injured or whether he went to the hospital.

The new details of the deadly Sept. 16 rampage are slowly emerging as local and federal law enforcement officials sort through thousands of pieces of evidence in what in effect are 12 separate homicide scenes. Lanier said she expects to release more details soon.

On the NewsChannel 8 show, Lanier reiterated that she thought active shooter teams from her department and others, including the U.S. Park Police, coordinated well and responded quickly and efficiently. In an interview Friday with The Washington Post’s Robert McCartney, she said other officers, including those from the D.C. department and from Naval District Washington, were inside the Navy Yard armed only with handguns before the tactical teams entered.

“It’s a horrible tragedy for the families, and of course I wish we could have prevented this to begin with,” Lanier said. “I think that’s what everybody has on their mind now. There are 12 families that have lost a loved one. Obviously, everybody wishes there was more we could do.”

The chief added: “We were able to save some lives. I wish we could have saved more.”

Lanier said that once the investigation is complete, she will use the information to review her department’s policies and practices and will share details with chiefs in other cities where there have been similar tragedies.

“Once all that stuff is analyzed, I think we’ll have a lot to take away from this incident, sadly, to help prepare for the next,” Lanier said.