The 30-year-old was taken into custody by police and has since been charged with the senseless killings.
Dr Richard Field, 49, and his fiancé Dr Lina Bolanos, 38, were murdered in their penthouse in South Boston last Friday night.
Police told the Boston Globe that the couple’s hands were bound and their throats slit open.
One of the officials also said that the killer had written a message of retribution on the wall and photographs of the pair had been cut up.
At the scene of the crime, authorities were confronted by 30-year-old Bampumim Teixeira, who opened fire on them.
“This individual had just killed two people,” Boston Police Commissioner William Evans said. “He had nothing to lose.”
Police shot back at Teixeira, who survived the hit and was taken to hospital.
Police believe the suspect was trying to rob jewellery from the pair.
Teixeira worked at a security guard at the same apartment complex where the doctors lived prior to 2016.
Suffolk District Attorney Daniel F. Conley dismissed allegations the suspect knew the pair.
“There is no evidence whatsoever at this stage that the defendant had a personal relationship with either Dr. Field or Dr. Bolaños,” Conley said at a news conference. “Nor is there any evidence to explain why he would attack them so viciously.”