(CNN) Two Boston doctors, engaged to each other, were found dead in their penthouse apartment, according to law enforcement.

Richard Field, 49 and Lina Bolanos, 38, were anesthesiologists at Boston-area practices, according to the couples' respective employers. Their bodies were found Friday.

Police arrested Bampumim Teixeira, 30, after receiving 911 calls reporting a person with a gun on Dorchester Avenue in South Boston.

Officers who confronted Teixeira in a dark hallway in the building believed he either pointed or fired a weapon at them and as a result discharged their own firearms, according to Suffolk County District Attorney Daniel Conley.

After a "violent struggle," according to police, he was arrested and taken to the hospital.

Teixeira was charged with two counts of murder and his attorney pleaded not guilty to both charges during an arraignment. He will be held without bail.

A backpack full of jewelry

During Teixeira's arraignment in his room at Tufts Medical Center, Suffolk Chief Trial Counsel John Pappas provided new details about the alleged slaying.

Bampumim Teixeira is arraigned from his hospital bed at Tufts Medical Center in Boston on Monday.

Pappas said that Boston police received two 911 phone calls -- one from the front desk at the luxurious Macallen Building in South Boston where the couple lived to report that it had received a concerned call from a friend of Field, and the other call from the friend himself. The friend allegedly received a text message from Field saying that he was in trouble and that there was a gunman in his apartment.

When police arrived, they entered the penthouse apartment and performed a sweep. They encountered Teixeira and a gunfight ensued, wounding Teixeira in his left hand, abdomen, and leg.

After Teixeira was detained, police entered the apartment and found Field and Bolanos dead. They also found a critical piece of evidence -- a black backpack in a "conspicuous" location full of jewelry, according to Pappas.

In a press briefing Monday, Conley said the black bag was not in Teixeira's hand when he was shot. He added that at least one knife was found at the scene.

During the hospital-room arraignment, Teixiera's eyes were closed for most of the hearing, though he was able to respond with one-word answers.

An "enormous loss"

Field and Bolanos were well-regarded anesthesiologists. Field was instrumental in founding North Shore Pain Management, according to a statement from the staff there.

"He was a valued member of the medical community and a tremendous advocate for his patients," North Shore Pain Management said in a statement on its website. "His tragic and sudden passing leaves an inescapable void in all of us."

Bolanos was a pediatric anesthesiologist at Massachusetts Eye and Ear, according to the clinic's CEO, John Fernandez.

"Dr. Bolanos was an outstanding pediatric anesthesiologist and a wonderful colleague in the prime of both her career and life," he said in a statement. "We will do all we can to support their families and our staff members who are processing this senseless tragedy and grieving an enormous loss."

Josh Golden, the owner of Luxury Residential Group, says that his company regularly works with the Macallen building to sell units and recently sold the penthouse across the hall from the couple's unit. He said the two were "very sweet and accommodating" during that process.

"We're shocked by the incident," Golden told CNN.

The building has high security, including security cameras in the lobby and a 24/7 concierge, Golden said. Additionally, access to the elevator for its penthouse level is regulated by a key fob, Golden said.

Motive still unclear

There is currently no evidence to point at any connection or relationship between Teixeira and the doctors, Conley said. He added that they are looking in to any kind of employment Teixeira may have had in the area and how he was able to access the doctors' home.

Teixeira has two previous larceny convictions, according according to Suffolk County District Attorney's Office spokesman Jake Wark. In the summer of 2016, Teixeira passed a note demanding money at a bank.

The second, virtually identical incident, which remained unsolved until Teixeira volunteered the information to law enforcement after his 2016 arrest, took place in August 2014 at the same location. Teixeira pleaded guilty to both crimes and was sentenced to a term of 364 days, with nine months to serve and the balance suspended for a three-year probationary term, according to Wark. No weapon possession or injuries were reported as a part of either incident.

A motive is still under investigation, he said.

Teixeira will appear in court on June 8 for a probable cause hearing.