Officials announced Friday that a 30-year-old Dorchester man is being charged with two homicides that took place in the neighborhood last Sunday — a double-shooting on the Southeast Expressway which killed a motorcyclist and another that left a woman dead later that night on Santuit Street.

In warrants obtained Thursday night, authorities allege Lance Holloman shot Scott M. Stevens, 32, of East Taunton and his 54-year-old father around 5 p.m. while they rode motorcycles southbound on I-93 near the Neponset Circle exit Sunday. Stevens later died of his injuries at Boston Medical Center on Wednesday. His father is expected to survive.

Holloman is also charged with murder for shooting 24-year-old Michaela Gingras. Gingras, a resident of Manchester, N.H., was found with fatal gunshot injuries several hours later inside 11 Santuit St. in Dorchester, officials said. She was pronounced dead at the scene late Sunday night.

An obituary for Gingras describes an athletic, persevering young woman. “She was small in stature but was fierce when protecting [her]self and those she loved,” it reads. “She had an amazing heart and soul.”

Gingras, the obituary said, “struggled with many things in life, and drug addiction like so many was one of them. She had just started to turn her life around when she was brutally taken from us.”

Holloman is being held without bail at the Suffolk County Jail on unrelated charges, State Police, Suffolk District Attorney Daniel Conley, and Boston Police said.

Franklin Police arrested Holloman on three outstanding warrants after he crashed a vehicle into a pole in that southeast Massachusetts town early Monday morning. A Franklin police report said Holloman gave them a false name and claimed that he had been kidnapped and was in fear for his life.

One of the outstanding warrants charged Holloman with unlawful possession of a firearm for a May 31 incident, in which he allegedly directed another person to throw a loaded handgun from a vehicle while fleeing a traffic stop, officials said.

Holloman was arraigned Monday afternoon in Dorchester Municipal Court. A $150,000 cash bail was imposed on the gun case, but bail was later revoked for 60 days on an unrelated pending case charging assault and battery and animal cruelty. An additional $500 bail was added for an unrelated pending case charging operation of a motor vehicle with a suspended license. “Holloman had earlier failed to appear in court on both these latter cases, triggering default warrants in both,” officials said.

The warrants charge Holloman with murder, armed assault with intent to murder, and other offenses. An arraignment date on the the murder and attempted murder charges has not yet been scheduled.

Investigations into both of Sunday’s shootings remain very active, officials said, and anyone with information on either one is urged to share it with Boston Police at 617-343-4470 or State Police at 617-727-8817.