1. 

   A shooting at a Colorado supermarket killed 10 people Monday, including a police officer who was the first to respond to the scene, authorities said. Police arrested a suspect, but didn't reveal his name or any details about the shooting at an evening news conference where Boulder police Chief Maris Herold fought back tears.

2. 

   The attack was the seventh mass killing this year in the US, following the March 16 shooting that left eight people dead at three Atlanta-area massage businesses. (Reuters Photo)

3. 

   Investigators had just begun sorting through evidence and witness interviews and didn't have details on a motive for the shooting at the King Soopers store in Boulder, which is about 25 miles (40 kilometers) northwest of Denver and home to the University of Colorado, said Boulder County District Attorney Michael Dougherty. (Reuters Photo)

4. 

   It follows a lull in mass killings during the pandemic in 2020, which had the smallest number of such attacks in more than a decade. (Reuters Photo)

5. 

   People are led out of a King Soopers grocery store after a shooting in the store, in Boulder, Colorado. (AP Photo)

6. 

   The slain officer was identified as Eric Talley, 51, who had been with Boulder police since 2010. (Reuters Photo)

7. 

   Identities of the other nine victims were not disclosed Monday night as police were still notifying their family members. (Reuters Photo)

8. 

   Law enforcement vehicles and officers massed outside the store, including SWAT teams, and at least three helicopters landed on the roof. (Reuters Photo)

9. 

   People stand near the scene where an active shooter was reported at a grocery store in Boulder, Colorado. (Reuters Photo)

10. 

    White House press secretary Jen Psaki tweeted that President Joe Biden had been briefed on the shooting. (Reuters Photo)