PHOENIX - A Christmas Day standoff ended with the death of an 11-year-old boy and a baby girl.

On Monday around 3:45 p.m., police officers responding to a shooting found a 38-year-old woman shot to death outside an apartment complex near Highland Avenue and 16th Street in Phoenix.

Police surrounded the apartment complex as a 45-year-old man, later identified as Anthony Milan Ross, the woman's estranged husband, was barricaded inside one of the apartments with the couple's two children.

During negotiations, which continued for hours, police said Ross threatened to kill the children. According to police, at one point he said he had already killed the children before changing his story to threats.

Police said shortly after 10 p.m. officers deployed a robot into the apartment and found the 10-month-old baby girl dead.

According to police, Ross started firing shots as officers continued using the robot to search for the 11-year-old boy inside the apartment.

Officers entered the apartment and exchanged gunfire with Ross. An officer was injured in the exchange, but it's not clear whether he suffered a gunshot wound or was hit by shrapnel.

Ross eventually surrendered, police said, and was taken into custody. He was not injured. The boy was found dead in the apartment.

Sierra Scott was celebrating Christmas with family elsewhere when she got a frantic call from her mother.

"We don't know what's going on," said Sierra Scott. Her mom lives inside The Highland apartment complex.

"We were at Christmas dinner with my other family and she called me hysterical saying that she heard over 15 shots," said Scott.

Scott rushed to the scene only to find dozens of police cars, armored trucks and fire engines. The streets surrounding the complex were completely shut down and her mom was unable to get out.

"My mom said everything's going on four doors down from the apartment," Scott explained.

"It just, it sucks even talking about it. It gives me goosebumps but I hope half of it isn't true," said Gibson Daoud.

Daoud and his family live in the apartment complex. Like many others, they were out at the time of the apparent shooting and were unable to return home for Christmas.

"I just can't believe that this would happen period, let alone on Christmas," said resident Kristen Alexander.

Officers believe the situation was likely related to domestic violence.