More than a year after her 23-year-old granddaughter was fatally shot in Roxbury, a Jamaica Plain woman now knows who authorities believe killed her “sweet child,” Briana Bigby.
“It means a lot,” 80-year-old Dolores Atkins said Thursday. “It shows that they really care about their job and getting these crazy people with guns off the street.”
Boston police and Suffolk County prosecutors announced a murder charge Thursday against Anthony Howard, 27, in Bigby’s death. They also disclosed the arrest of a 29-year-old Dorchester man accused of murder in an unrelated slaying in the South End in 2012.
Howard, of Dorchester, was already in custody awaiting trial in a separate firearms case, officials said. A date has not been set for him to appear in court on the murder charge or on charges that he shot three other people on the same day.
Bigby was a 2009 graduate of Concord-Carlisle Regional High School, which she attended through the Metropolitan Council for Educational Opportunity Inc., said Aaron Joncas, the school system’s Metco director. He said Bigby’s younger sister is also enrolled in the program.
After high school, Bigby attended college in Baltimore, her grandmother said.
“To take her at that age . . . is devastating,” Atkins said. “We don’t want anyone to forget her.”
Bigby was mortally wounded near 310 Walnut Ave. at about 3:15 p.m. on June 1, 2013, while she was with a 23-year-old man, officials said. Bigby’s family has said the man was Bigby’s boyfriend, who was also wounded in the shooting. The family has also said they believe the boyfriend was the target of the gunfire because he had previously been fired upon.
“I knew there was nobody who [was] looking for her,” Atkins said.
Howard was also charged with armed assault with intent to murder in the shooting of Bigby’s boyfriend. He is also accused of shooting two other men, ages 21 and 26, on Humboldt Avenue about 5:40 a.m. earlier that day, officials said.
In that shooting, Howard has been charged with two counts of armed assault with intent to murder and a second offense of illegally possessing a firearm.
Howard is in custody on firearm and ammunition charges. In that case, Richard Lee Allen, 27, was found in Dorchester suffering from multiple gunshot wounds on Nov. 28, 2012, according to an affidavit for a search warrant application filed in Suffolk Superior Court.
Police believe that Howard and Allen were involved in a violent struggle in the basement of the building where Howard lived. Allen called 911, according to the affidavit written by Detective Richard L. Medina. Medina wrote that Allen and Howard are associates of different gangs.
Howard has pleaded not guilty to those charges.
In an unrelated case, authorities also announced Thursday that they had arrested Luis Diaz in the killing of Orlando Guerrero, 42, who was shot on Windsor Street in the South End on Dec. 15, 2012.
Diaz appeared in Suffolk Superior Court Thursday, where he pleaded not guilty to first-degree murder, armed robbery, and unlawful possession of a firearm and ammunition.
He was ordered held without bail.
Jose Carrasquillo, 43, was charged in Guerrero’s death last year and pleaded not guilty, court records show. Carrasquillo has entered into a plea agreement with prosecutors, said Assistant Suffolk District Attorney Holly Broadbent.
Diaz’s lawyer, James J. Coviello, said witnesses in the case “have an interest in exculpating themselves.”
“I didn’t hear any argument concerning a speck of forensic evidence,” Coviello said.
Police Commissioner William B. Evans acknowledged the detectives and prosecutors who worked on both cases.
“May these arrests bring some level of comfort to the victim’s families,’’ Evans said in a statement.
Suffolk District Attorney Daniel F. Conley credited the joint efforts by police and prosecutors for resolving both killings months after they occurred.
“These arrests reflect our shared policy of thorough investigations in every case,” Conley said in a statement. “Police and prosecutors never give up on these cases or the families we work with.”John R. Ellement of the Globe staff contributed to this report. Laura Crimaldi can be reached at email@example.com. Follow her on Twitter @lauracrimaldi.