A Boston man was convicted of first-degree murder in the 2015 killing of a Dorchester man after prosecutors said he and two accomplices mistakenly entered the victim’s apartment while looking for someone else.

A Suffolk Superior Court jury on Thursday found Victor Arrington, 40, guilty of first-degree murder, home invasion, armed assault with intent to murder, unlawful possession of a firearm, and two counts of kidnapping, Suffolk District Attorney Kevin Hayden announced. Arrington is scheduled to be sentenced on Tuesday. 

Under Massachusetts law, a first-degree murder conviction carries a mandatory sentence of life in prison without the possibility of parole.

The verdict came after Arrington’s first trial ended in a mistrial in May 2024 when jurors were unable to reach a unanimous verdict.

Prosecutors said Arrington and two other men planned to assault and rob a man who lived on Harvard Street in Dorchester on March 31, 2015. Instead, they forced their way into the apartment of Richard Long, 37, an ironworker and member of Iron Workers Local 7 who had no connection to the intended target.

According to prosecutors, the intruders bound Long and his fiancée with electrical cords. “Realizing that they had entered the wrong home, the men decided to kill Long and his fiancée to cover their tracks,” Hayden said.

Prosecutors said the men stabbed Long with a knife, shot him in the head, shot Long’s fiancée in the head, and poured bleach on their bodies before setting fire to the kitchen and fleeing. Long died at the scene. His fiancée regained consciousness and rescued the couple’s infant son from the apartment before escaping to a neighbor’s home for help.

Arrington was arrested in July 2016. A second defendant, James Boyd, 33, is charged with home invasion, assault with a dangerous weapon, and two counts of kidnapping. He is expected to change his plea on July 1, according to the district attorney’s office.

A third alleged accomplice was identified during the investigation but was never charged because he was killed in an unrelated homicide in April 2015, Hayden’s office said.

The retrial was also notable for prosecutors’ use of location information stored in the Frequent Location History feature on Arrington’s iPhone. Following an extensive evidentiary hearing, the court allowed prosecutors to present the digital evidence to jurors over the defense’s objection, according to the district attorney’s office. 

“This team effort helped secure a just verdict in an extraordinarily harrowing case, notable not only for its shocking violence against completely innocent victims but also for the precedent it set in the use of advanced digital evidence,” Hayden said. “But most important of all is the opportunity for Richard Long’s family and loved ones to see someone held accountable for this terrible crime.”