They didn't speak to reporters as they took pictures of cards, looked through the flowers and consoled each other.
Jayna Murray's body was found Saturday morning when an employee opened the athletics store. A 27-year-old woman who had been sexually assaulted and bound was taken to an area hospital with non-life-threatening injuries.
Two victims closed the store at 9 p.m. Friday, police said, and left at about 9:45 p.m. One of them realized that she had left something in the store, but she did not have the keys to re-enter, so she called her coworker, who had a set of keys, and they arranged to meet back at the store. As they went back in at about 10:05 p.m., two masked men dressed in black also entered.
Investigators are checking surveillance video from nearby stores for clues but said Tuesday they did not know yet if that was going to help, NBC Washington's Pat Collins reported. They hope to find footage of the culprits unmasked.
Police said they have a great deal of forensic evidence but did not say if that includes DNA evidence.
Other than their clothing, the only description of the men is that one was about 6-feet tall while the other was about 5-foot-3.
On Wednesday, police said they are following up on about 40 text message tips, Collins reported.
Anyone with information should call police at 866-411-TIPS. The total reward in this case is now more than $140,000, Collins reported.