A woman and a badly injured baby were taken to separate local hospitals after being shot on Stratton Street in Dorchester about 20 minutes before midnight on Monday, Boston Police said, noting that the baby had sustained life-threatening injuries.

The violence took place outside 81 Stratton Street near the intersection of Ames Way in the Franklin Field housing development. Police Commissioner Michael Cox said that a ShotSpotter detected the gunfire, which he called a “cowardly” and “heinous act” in an early morning press conference on Tuesday. “I can’t think of any reason why somebody would shoot both a female and a young child,” he said.

No arrests have yet been made in the shootings, but police “have good information,” Mayor Wu said on Tuesday morning and are asking for the public's help “in anything that anyone might have seen.”

When officers arrived at the scene, Cox said, they discovered the victims in a driveway area. The gunman was believed to have fled the scene and the victims, who had been taken to local hospitals, he said, where “the child has life-threatening injuries, and the female appears non-life threatening currently.”

He added: “We're in the early stages of an investigation here, and we are canvassing the area and doing all we can to certainly find out more about this incident.”

Mayor Wu also weighed in on the case Tuesday morning, saying she was “horrified to have heard the news,” but is thankful BPD and EMS acted swiftly.

“First responders were there quickly,” she noted. “They were able to quickly transport the victims and provide medical care. Things could have been even worse.”

She added, “There are now community members who will be impacted, families that are going to live with trauma, and we're pushing out every resource that we can to make sure there's accountability in this case.”

As the investigation continues, trauma teams have been sent to the neighborhood.

The mayor said: “There is no possible reason for violence in our city, especially when it comes to young people and our very young children. I know that the police department is working through their investigation. They have good information but are continuing to ask for the public's help and support.”

She noted: “If you look at the rate at which Boston Police has been able to make an arrest after an incident, they have been working very well with the community. We're very thankful and very proud of the strong relationships that our department maintains with all of our neighborhood associations and community leaders. We've seen this feedback loop, and this partnership really makes a difference in delivering justice.”

Wu and Cox advise anyone who may have seen or heard anything related to the crime to contact the BPD homicide unit at 617-343-4470. Those who want to remain anonymous can do so by calling 1-800-494 TIPS.

The scene of Monday’s shootings is a short distance from 50 Ames St., where five people were shot a year ago – nearly to the day – in a courtyard of the housing complex. Two children were among the victims in that incident. All survived the attack, but one victim, a 15-year-old girl, was shot in the head and hospitalized for three months.

In December she finally returned home to her 11-year-old brother, who was also injured, but not critically. In that case, Boston Police arrested Gianni Johnson of Dorchester, and Micah Ennis of South Boston, in connection with the shootings.