A former D.C. police officer was sentenced to 15 years in prison Friday in connection with the 2009 attempted robbery of an alleged drug dealer, which resulted in the fatal shooting of one of the co-conspirators during the botched crime.

D.C. Superior Court Judge Michael L. Rankin told Reginald Jones, 42, that he betrayed his uniform when he served as a lookout in his police cruiser so that five other men could commit a robbery. Jones was on duty when the crime occurred on Dec. 1, 2009, at Fourth Street and Livingston Terrace SE.

At one point, Tyrone Herring, whom authorities identified as a drug dealer, tried to fight off his assailants while his girlfriend ran to Jones’s squad car for help. Jones sped off.

During a struggle during the robbery attempt, Arvel S. Alston, 40, was accidentally shot by his son, Arvel Crawford, 20, who was also part of the scheme.

“A police officer betrayed the public trust, tarnished the shield that every one of us looks to for safety and justice,” Rankin said, at times pointing his finger at Jones.

Jones, whose arms and ankles were shackled, wiped away tears during the sentencing. He had pleaded guilty to second-degree murder and conspiracy to commit robbery.

Assistant U.S. Attorney John Giovannelli read from the D.C. police’s “Oath of Honor” in asking for a 20-year sentence.

“On my honor, I will never betray my badge, my integrity, my character or the public trust,” Giovannelli read. Jones, he said, “betrayed that trust.”

Jones’s attorney, Brian K. McDaniel, asked Rankin to sentence his client to 12 years or less and had initially asked for a three-year sentence. “Law enforcement officers, like any individuals, make mistakes, and this was a big one. He admits that,” McDaniel said.

Before Jones was sentenced, he apologized to the family of the victim, his own family and the citizens of the District and asked Rankin for “a second chance.” He was on the force for about six years and assigned to the 4th Police District’s gun-recovery unit.

Jones was the last of the five men sentenced in the case. Roshun M. Parker, 29, was sentenced to three years in prison; Crawford was sentenced to 18 years; and Jarvis Clark, 20, was placed on supervised probation. Raylen D. Wilkerson, 34, the only defendant who did not plead guilty, was sentenced to 21 years after a jury found him guilty of first-degree murder, obstruction and related charges.

Prosecutors said the men, along with Alston, devised a plan in Wilkerson’s Temple Hills auto accessory shop to rob and kidnap Herring. Herring suffered minor injuries in the robbery attempt. Prosecutors say Jones, who grew up with Wilkerson, was brought in to serve as a lookout. His job was to sit in his patrol car and scare away witnesses.

Jones was terminated from the force after his arrest. In a statement after Friday’s hearing, D.C. Police Chief Cathy L. Lanier said his sentencing “reinforces to the community that people who commit crimes in this city will be treated equally.”

Weeks before his sentencing, Jones spoke to a Washington Post reporter from the D.C. jail. Jones, who grew up in Hyattsville, said he always wanted to be a police officer. It was in his family: Three uncles and three cousins were officers. He was sworn in on Jan. 25, 2004, and he had ambitions of becoming chief of police. “It was a good feeling, being an officer,” he said.

But around November 2009, Jones said Wilkerson approached him about “getting some money” from a drug dealer. Wilkerson, Jones said, owed him $8,000, and Wilkerson told him it was the way to get the money back. “I was reluctant. I didn’t want to get involved in anything like this,” Jones said.

Court records show that Jones was having financial problems and that his four-bedroom home in Upper Marlboro was in foreclosure. Jones, who said he earned about $90,000 a year with overtime pay, said he planned to use the money to help him buy a six-bedroom home.

“I’m not a dirty cop. I did a lot of positive things,” Jones said. “But there’s a lot of pressure on police. We don’t make a lot of money.”