The terrified woman called 911 at 11:20 a.m to report a homicide. Two distraught boys, just 4 and 5, had banged on her door with panicked cries that their mother was lying on the floor of their apartment upstairs and would not wake up.
It took 14 minutes and two more frantic calls for Boston police to arrive.
Police acknowledged yesterday that the dispatcher had sent a cruiser to the right street address, but in the wrong neighborhood. Instead of rushing to a Dorchester apartment building Sunday morning, police raced to Downtown Crossing, to a Malaysian restaurant two blocks from Boston Common.
Questioned about the delay yesterday, police attributed the error to a computer mapping system that was installed in January and the failure of the dispatcher to determine the precise neighborhood.
Soon after police arrived at the three-story apartment at 11:34, according to an internal police document, they found Melissa Santiago, a 29-year-old mother of six, face down on the kitchen floor, dead from multiple stab wounds.
"It was completely out of control," Santiago's neighbor, who asked not to be named because of safety concerns, said yesterday. "I was very clear that I'm here on the first floor. I'm with these kids by myself, and I fear for my life."
Police say Santiago had been dead for several hours by the time officers found her body.
"Sadly, in this particular situation, our arrival time had no effect on Melissa's tragic outcome," said Elaine Driscoll, spokeswoman for the Boston Police Department.
The mistake underscores the confusing nature of Boston's road patterns, where streets of the same name exist in different neighborhoods. The police were heading to Washington Street on Sunday. There are at least three streets with that name in the city: in downtown, Dorchester, and West Roxbury.
"We monitor our technology very closely, and we're going to review how this could have occurred," Driscoll said. "In addition, we're going to send the call taker for some additional training, just to ensure that this doesn't happen again."
Friends of Santiago said that made little difference to them.
"What if Melissa would have been alive?" said Stephanie Santiago, who described herself as one of Santiago's closest friends and is not related to the victim.
"I'm really upset," said Santiago, 20, who lives in Dorchester and is trying to raise money to pay for her friend's funeral. "I don't even have words. That shouldn't happen. Not to her, not to nobody. Not to my worst enemy."
Melissa Santiago's boyfriend - Jose Torres, a 26-year-old unemployed cook - was arrested later Sunday and charged with murder. He was sent to Bridgewater State Hospital for a psychiatric evaluation the next day, after a court clinician told a Dorchester District Court judge that Torres suffers from depression and post-traumatic stress disorder.
The neighbor said that when the boys first came to her apartment for help, she went upstairs with them to find Santiago's two other children, a 2-year-old girl and an 8-month-old girl.
She saw the body. "It was just horrific," she recalled.
At 11:20, according to the internal police document, Santiago's neighbor called 911 and spoke with the operator for almost three minutes. The operator, following procedure, took down the address and the details the emergency.
The operator, who is not identified by name, sent a computerized message that was dispatched to officers in District 1, the area that covers Boston's Downtown Crossing, Beacon Hill, Chinatown, and Charlestown.
The caller is "upset," reads the message. "Immediately believes there was an homicide on the 3rd floor. The person has the kids with her. . . . Please hurry before he come back [sic]."
At 11:24, the operator sent another message to officers: The caller does not want to give further information and is afraid to go to the third floor.
At 11:26, the police, then at Downtown Crossing, began to suspect they had the wrong address, according to Driscoll.
At 11:29, the operator sent a third message from the caller, who was "very upset because police are not there yet."
At 11:31, officers from District 11, which covers Dorchester, were dispatched. They arrived at 11:34, 14 minutes after the operator received the call and about 10 minutes after the operator entered the information into the computer system.
Driscoll said the average response time for police to arrive on the scene is seven minutes after they receive the 911 call.
Santiago's neighbor said yesterday that during her first call, she told the operator she lived in Dorchester, close to Codman Square. "I told them," she said. "Codman Square is down the street. You all need to get somebody here now."
Driscoll said the caller never provided 911 operators with the neighborhood.
"What we have is she said 689 Washington St., but did not give a specific location," Driscoll said.
But Driscoll acknowledged that the 911 operator should have tried harder to get the neighborhood.
In January, the state upgraded the city's 911 system with a computerized mapping system known as MapStar, which would help operators figure out the exact locations of emergencies. When the operator enters an address into the computer, the system pulls up the exact location.
On Sunday, the address that popped onto the screen was downtown, Driscoll said. A secondary computer system called up three possible Washington Street addresses but the operator assumed that MapStar had provided the correct address.
"In this particular case there was an over-reliance on the new technology," Driscoll said.
Globe correspondent Matthew P. Collette contributed to this report. Maria Cramer can be reached at firstname.lastname@example.org.