A Maryland man was fatally shot Wednesday night in Northeast Washington, part of a spasm of violence in the District that included more than a dozen robberies stretching into Thursday morning.

The crimes occurred at all hours in every quadrant of the city except Southwest, according to D.C. police. They included a robbery downtown on M Street about 7 a.m. Thursday as people were heading to work and two assaults south of Dupont Circle a half-hour apart early Thursday that police said appeared to be related.

On Wednesday evening, according to police, a 12-year-old boy was struck and robbed by three older juveniles who took his Halloween candy and an iPhone as he was trick-or-treating along N Street in Georgetown.

D.C. Police Chief Cathy L. Lanier, appearing Thursday morning on a WTOP radio call-in show, said there were two instances of candy bags being snatched in the city Wednesday. She said nine robberies occurred during what she called the “bewitching hours” of Halloween, but it was unclear how many could be linked to street celebrations.

Hundreds of extra police officers had been dispatched across Washington for Halloween, and Lanier toured the city’s Halloween hot spots Wednesday night. She also responded to the fatal shooting, which occurred about 9:45 p.m. in the 2000 block of Fourth Street NE.

Police said the victim, identified as Anthony Weathers, 25, of Suitland, was shot multiple times in an alley behind the 300 block of V Street NE and died at the scene. Lanier, speaking on the radio program, said detectives had spoken with several possible wit­nesses.

Another shooting occurred about 8:50 p.m., when police said a man was shot in the neck in the 2700 block of Naylor Road SE. The victim was taken to a hospital, but police had no immediate update on his condition.

Police are investigating two similar attacks against groups of people that occurred blocks apart in Northwest Washington between 2:30 a.m. and 3 a.m.

The first occurred in the 1200 block of 20th Street NW, where police said two women and a man were attacked. The man was cut, one woman was knocked to the ground and the other woman was bitten in the hand, according to police.

A half-hour later in the 1700 block of Rhode Island Avenue NW, police said, two men were attacked by four people who knocked one man to the ground and then kicked him until he was unconscious.

Officer Araz Alali, a police spokesman, said detectives are investigating whether the same people are responsible for both attacks.

Robberies reported around the city included a man robbed at gunpoint in the 1000 block of Rhode Island Avenue NE, a man robbed of his wallet at gunpoint in the 1800 block of West Virginia Avenue NE and a robbery in the 1000 block of Geranium Street NW in which police said the attacker fired an errant shot at the victim.

Several robberies involved masked assailants, Alali said, including one at 4 a.m. in the 7300 block of Georgia Avenue in which one gunman wore a ski mask and the other a skeleton mask. On Naylor Road SE, Alali said, a robber wearing a ghoul mask knocked a man to the ground.