A semiautomatic handgun that D.C. police say was used by a 22-year-old man who fired at officers Tuesday night in southeast Washington. Two officers returned fire, killing Marqueese Alston. (N/A/D.C. police)

A 22-year-old man who was fatally shot by D.C. police Tuesday night in Southeast Washington had fired on the officers after they chased him into an alley, the District’s police chief said.

The man who was killed, Marqueese Alston, of Southeast Washington, had been released from prison in March after serving 30 months for robbing a man of his car at gunpoint, according to court records.

Alston was on supervised release at the time he was killed, being monitored by the Court Services & Offender Supervision Agency. Police said he was wearing a GPS bracelet to keep track of his movements. He was barred from possessing a gun and from leaving the District.

D.C. Police Chief Peter Newsham said officers encountered Alston during a saturation patrol effort targeting guns and repeat offenders in Ward 8, an area of the city east of the Anacostia where nearly half of the District’s 70 homicides have occurred this year. Newsham ordered the extra officers there in May.

“This incident is an example of how extremely dangerous this can be,” Newsham said of his crime plan. He added, “There is a significant amount of evidence that the decedent was armed, he was a felon, he was under supervision and he fired at our police officers. To save their lives, the police officers returned fire.”

Alston’s great-aunt, Brenda Price, 68, disputed the police account and said she believes her nephew was a bystander who got shot as police jumped from their cars to confront a group of people. She said he lived near where he was killed and was seeking a job to care for his fiancee and his young daughter.

“I don’t believe he had a gun,” Price said. “Why would he shoot at police if he just got out of prison and is trying to get on with his life?” She said she wants to see the police body-camera videos. “There’s a whole lot of questions,” she said. “Our family is very upset by what went down.”

The incident occurred abut 7:10 p.m. in the 3700 block of First Street SE, near Wayne Place, in the southernmost part of Congress Heights and near Washington Highlands.

Newsham said uniformed officers in marked patrol cars pulled up into the block, where a group of people had gathered. He said Alston fled into an alley while reaching into his waistband, a typical hiding place for a weapon.

Officers chased Alston, Newsham said, and Alston shot at them. Two officers returned fire. The chief declined to say how many shots were fired. No bystanders or officers were struck. Alston was pronounced dead on the scene. In addition to the semiautomatic handgun, which police photographed lying in grass and weeds, Newsham said Alston had a gun magazine containing additional rounds of ammunition.

Authorities said the officers’ body cameras were on. Investigators and other city officials are reviewing the contents as the mayor makes a decision on whether to publicly release the footage.

Court records show that in September 2015 Alston was charged with armed carjacking after police said he put a gun to the head of a motorist in Northeast Washington and demanded the keys. The victim told police he had met up with Alston, known as “Queese,” to buy marijuana.

In January 2016, Alston pleaded guilty to a reduced charge of robbery and to one count of illegal possession of a handgun. He was sentenced to 30 months in prison. Though 20 years old, he qualified for the Youth Rehabilitation Act, which is available to some offenders under the age of 22. It allows for shorter sentences for some crimes and opportunities for offenders to wipe out their criminal records.

In September 2016, Alston wrote to the Superior Court judge and pleaded to be freed from prison in Cumberland, Md., and allowed to serve the remainder of his sentence in a halfway house. He noted that his family had become homeless, and he had a fiancee and a newborn daughter.

Alston wrote it wasn’t fair for his new family to be homeless “because of my immoral conduct.” He apologized for his crimes, stating, “I understand my past actions were not acceptable.”

The judge denied the request, saying Alston’s sentence was at the low end of guidelines. The judge said because Alston had used a gun, “a reduction in the sentence is not warranted.”