A prominent Virginia physician who was on vacation in Belize over the weekend was shot to death along with his tour guide — who had been targeted by a local gangster, officials said Tuesday.

Dr. Gary Swank, 53, an interventional cardiologist at the Carilion Clinic in Roanoke and the medical director of the clinic’s Cardiac Catheterization Lab, also taught at Virginia Tech's medical school, according to the hospital. The State Department also confirmed Swank's death.

"We are heartbroken at the loss of our incredible husband and devoted father Gary Swank, M.D., who we will forever cherish," his family said in a statement released by the hospital Tuesday.

"His senseless murder has left us to mourn a purposeful life ended too soon."

Swank, an avid fly fisherman, was traveling with his wife and school-age children, neighbors told NBC affiliate WSLS in Roanoke.

Dr. Gary Swank Carilion Clinic

Swank, the married father of three, and his guide, Mario Graniel, 53, had gone out in their skiff Sunday at about 11:30 a.m. local time and were later found shot to death, police in San Pedro said.

Graniel was found "in a fetal position behind the steering wheel of the skiff" and had been shot four times, according to a police statement. Swank's "lifeless body" was "floating face down in the lagoon about 30 feet away from the skiff" with four gunshot wounds, police said.

They were fishing when "a dark-color skiff passed by and open fire on the boat," police said.

Police believe the gunmen were targeting Graniel, who "had a misunderstanding with one of the local notorious gang" figures of San Pedro, Belize Police Commissioner Chester Williams told local Channel 5 news.

Someone had shot at Graniel's home the night before the double murder but he still went to work Sunday despite these threats, police said.

Asked if Swank was a victim of circumstance, at the wrong place at the wrong time, Williams said: "That is surely the case."

Melanie Wilhelm, Swank's sister, told NBC News on Tuesday that her older brother was her "protector" and that he was loved by everyone who met him. Wilhelm said she was shocked that Graniel took her brother out for a fishing trip knowing that someone was after him.

"Whatever was going on with the guide, I’m just shocked and appalled that the guide wouldn’t have told my brother that today is not a good day to go out," Wilhelm said.

Wilhelm choked back tears thinking about how her brother's children would have to go forward in life without their father.

"I'm going to work hard to make sure they know that their dad is always with them and he loved them more than anything," Wilhelm said. "They have to just believe that he will always be with them and he will always look over them."

Mario Graniel, a tour guide in Belize. Channel 5 Belize

“I am shocked and saddened by the death of Dr. Gary P. Swank. I ask all Virginians to remember Dr. Swank’s wife and children as they deal with this unthinkable tragedy," U.S. Rep. Ben Cline, R-Va., the doctor's congressman, said in a statement. "My office stands ready to assist Dr. Swank’s family in the coming days.”

Swank's sudden death stunned coworkers and patients.

"He saved my life, and every time I went to his office, he was a very knowledgeable, patient and caring person," patient Teresa Hodges told WSLS. "He's part of my life."