Police arrested an 18-year-old Wednesday in relation to a double shooting that occurred in Dorchester on Sunday, authorities announced. 

The evening incident at 69 Kingsdale St. resulted in the hospitalization of a woman with serious life-threatening injuries and a man with injuries that were not believed to be life-threatening. 

Jaynell Sumler, 18, of Dorchester, was arrested Wednesday around 1:30 p.m., according to a statement from the Boston Police Department.

He was charged with assault to murder (two counts), carrying a firearm without a license, possession of ammunition without an FID card, and discharging a firearm and striking a building, police said. 

Sumler appeared in court Thursday morning, where he pleaded not guilty to the charges, according to court records. 

The Kingsdale Street shooting marked the fifth shooting in Boston in the past week and Dorchester’s second shooting on Mother’s Day. 

In the immediate aftermath of the Kingsdale Street shooting, BPD Superintendent Paul McLaughlin said the incident appeared to be “directed” rather than “something that people in the neighborhood should be concerned about specifically.” 

Police did not provide an update on the current medical condition of the victims.