A 19-year-old Dorchester man will spend the rest of his life in prison for robbing a Turkish immigrant at gunpoint, then shooting and killing him in the chase that followed, Suffolk County District Attorney Daniel F. Conley announced.

After four days of testimony and a little more than a full day of deliberations, a Suffolk Superior Court jury found GARY JOHNSON (D.O.B. 10/28/89) guilty of first-degree murder for the Nov. 1, 2007, shooting of 47-year-old Mumin Manavoglu of Brockton, which left the shopkeeper critically injured until he succumbed to his wounds the next evening.

Jurors convicted Johnson under the theory of felony murder – a homicide committed in the course of a violent felony. In this case, that felony was armed robbery, for which jurors also convicted Johnson. Suffolk Superior Court Judge Frank Gaziano sentenced Johnson to the mandatory term of life in prison without the possibility of parole.

Before handing down that sentence, Gaziano listened as Assistant District Attorney Cory Flashner read a statement from Yasime Manavoglu, the victim’s widow and the mother of his three children, who now provides for her family by taking over her husband’s Norfolk Street pizza parlor – an obligation that takes her out of the home when her children need her most.

“My children don’t see me anymore because I have to work all the time,” the statement read. “I never get to have breakfast with my children. My children miss me. My children cry every night. And I don’t get to tuck my children in at night for bedtime. I have to be everything to them, both mother and father. They miss their dad so much.”

Manavoglu was “living the American dream,” prosecutors said at trial, demonstrating that he had come to America, obtained legal citizenship, and opened the Stalex Pizza shop in Dorchester. He started his work day at about 6:30 each morning – including the day he didn’t came home.

At about 9:30 that morning, testimony showed, Johnson walked in wearing a black hooded sweatshirt, black pants, and a black knit cap. Making his way behind the counter, he brandished a 9mm semiautomatic firearm and demanded money from the cash register.

Manavoglu’s partner at the restaurant gave Johnson about $80 in a plastic bag, which Johnson carried out of the store. Manavoglu followed him.

Outside the store, Manavoglu grappled with the younger man, who pulled the gun from his pocket and fired a shot. That shot did not hit Manavoglu but caused him to fall down as Johnson continued to run down Norfolk Street. He got back on his feet and chased after Johnson.

Johnson turned. He raised the gun. He pointed it at Manavoglu. He fired a second time. The shot hit Manavoglu in the head, mortally wounding him. Johnson turned left onto Edson Street and kept running.

Boston Police officers on routine patrol in the area spotted Johnson making the turn onto Edson. They also observed him to stop, turn, and run away from their marked cruiser. As the officers continued toward Norfolk Street, they observed the crowd that had gathered where Manavoglu was shot.

The officers relayed their observations to Boston Police dispatchers. Emergency medical technicians responded to assist the victim and all available police units were called to search for his assailant.

Johnson’s hat, sweatshirt, and gun were recovered in the one-block area bordered by Norfolk Street, Woodrow Avenue, and Milton Avenue. Johnson was apprehended as he tried to hide behind a shed in the back yard of a Woodrow Avenue residence. In a tape-recorded, post-Miranda statement to Boston Police homicide detectives, he admitted to using the firearm in the armed robbery, pointing the firearm at the victim on the street, and pulling the trigger. He also indicated that he was sorry Manavoglu was shot.

“It gives us no pleasure to see a young man of 19 go to prison for the rest of his life,” Conley said after sentencing. “It’s a waste – but it’s a waste of his own choosing. Gary Johnson chose to commit an armed robbery. Gary Johnson chose to bring a loaded gun. Gary Johnson chose to point it at a father of three. Gary Johnson chose to pull the trigger not once but twice. That’s a series of decisions that add up to first-degree murder, all made by Gary Johnson, who knew the risks and could have stopped himself at any time.”

Flashner was second-seated at trial by Assistant District Attorney Gretchen Lundgren. Johnson was represented by attorney William Keefe.