LEFT: Arthur Baldwin Jr., 30, a Secret Service officer, was killed in a robbery on Dec. 15, 2015. RIGHT: Davonte Washington, 15, was fatally shot in a Metro station on March 26, 2016. (Family photo; Courtesy of Victor Leonard)

A little more than three years ago, Maurice Bellamy, then 17 years old, was with two friends when he walked up to a parked car and tried to rob the man inside. As the off-duty Secret Service officer tried to fight him off, Bellamy shot the man multiple times.

Three months after that shooting, which left 30-year-old Arthur Baldwin Jr. dead, Bellamy was on the platform of the Deanwood Metro station. Davonte Washington, 15, there with his mother and two younger sisters, was waiting for a train to go to a barbershop to get a haircut for the upcoming Easter Sunday church service. A glance from the younger teen enraged Bellamy, and he pulled out a .38 caliber pistol and shot Davonte twice.

On Friday, Bellamy, now 20, showed no reaction as a D.C. Superior Court judge sentenced him to 65 years in prison for the slayings. Bellamy was convicted of two counts of first-degree murder after a week-long trial last March.

The chilling killings rippled through the nation’s capital as Bellamy’s troubled life that led up to the murders became public.

Bellamy’s attorneys, Steven ­Kiersh and Kevin McCants, asked Judge Juliet McKenna for leniency, reminding the judge that Bellamy was a teenager at the time of the shootings. They said Bellamy was “remorseful” for the killing of the youth at the Metro station, and they maintained that it was one of Bellamy’s friends, not him, who pulled the trigger during the robbery of the Secret Service officer. McCants argued that his ­client could be rehabilitated through counseling and maturity.

Arthur Baldwin Jr.’s family put together this collection of mementos after his murder. (Keith L. Alexander/The Washington Post)

“What he did as a juvenile should not define how he will be his entire life. It defeats the rehabilitative efforts. This young man is salvageable,” McCants said.

Bellamy had struggled with his temper since he was in grade school, and later, when he was a teen, his schooling was interrupted when D.C. officials did not immediately enroll him in classes, according to a Washington Post report after his arrest.

During the trial, Bellamy’s mother, Keisha Shelton, who sat behind her son Friday as he was sentenced, testified that he began showing impulse-control issues when he was in the second grade.

A doctor prescribed a medication to help him control his temper and reduce anxiety. His mother enrolled him in a private school in Maryland where teachers were able to focus Bellamy’s energy into his schoolwork. He was a speaker at his eighth-grade graduation.

But in 2013, Bellamy’s family moved to Southeast Washington. Shelton testified at trial that D.C. school officials initially told her that Bellamy could remain at his Maryland school, even after she moved to the District, but that didn’t happen. For five weeks, Bellamy, then 15, drifted while his mother tried to get the school system to enroll him at Ballou High School, which was within walking distance of the family’s new home.

When Bellamy finally started classes, his absences, bursts of anger and failing grades quickly piled up.

During his freshman year at Ballou, Bellamy was arrested on a charge of simple assault for threatening a school employee. He eventually dropped out of school.

Assistant U.S. Attorney Laura Bach said Bellamy had been in fights since he was in preschool. His mother, teachers and others tried to help direct Bellamy, but they were unable to change his path, Bach said.

“This is not his mother’s fault. This isn’t the school’s fault. This isn’t even the fault of negative peers or gangs,” she said. “He likes to fight. He’s been violent his entire life and will fight for no reason.”

Bach said: “I wish he could be rehabilitated. I don’t know if he can be. He needs to be locked up for the rest of his life.”

Bach also told the judge that since his arrest, Bellamy has been charged with four assaults while in jail in the District — two alleged attacks on correction officers and two on fellow inmates. Prosecutors asked the judge to sentence Bellamy to 80 years in prison.

Family members of the victims tearfully asked McKenna to ensure Bellamy is never allowed back in society.

Arthur Baldwin Sr., a retired police officer who spent time on a SWAT unit, told the judge his son wanted to follow him in law enforcement. “I never thought I would be here one day, for my own child, talking about my son, my only son,” Baldwin said in court as his wife, Helen, stood nearby.

Baldwin said his son was a student at Howard University when he covertly applied to work for the Secret Service. Baldwin said his son telephoned him at 2 a.m. to tell him, “Daddy, they accepted me.”

Davonte’s mother, Rashida Washington, who testified during the trial about chasing Bellamy after the shooting, stood before the judge holding her 2-year-old son Kayden in her arms. He was born just months after Davonte was killed.

“This young man took a great young man away from his family,” Washington said. “My son did not deserve how his life ended. It’s not fair. I am here for his just due.”

Before issuing her sentence, McKenna praised the families of the victims for their “amazing strength and resilience.” She called the cases “a tragic outcome for all involved.”

McKenna said she did not give Bellamy the 80 years the prosecution requested because he did not have any prior adult convictions. The judge added that she “hoped” Bellamy would use the time in prison to “better himself.”