The man who police say shot his stepfather and mother to death in the Bronx on Thursday, then fatally turned the gun on himself, was a quiet loner whose behavior had become more erratic in recent months, the stepfather’s friends and business associates told the Daily News. Francisco Ferrer and Paula Lopez, both 57, were found dead in their second-floor apartment in an apartment building on Southern Blvd. near Avenue St. John in the South Bronx. Lopez’s son, Tonatiho Rojas Lopez, 34, was found slumped outside in front of the building, shot in the head and torso, a gun at his side, cops said. Ferrer immigrated from Puebla, Mexico around 40 years ago and for the past 20 years had operated Jerome Tobacco on Jerome Ave. in the Bronx, a wholesale store selling containers, coffee cups, and plastic and paper bags to other businesses in the area. Cops found the victims’ 34-year-old son, Tonatihu Rojas Lopez, slumped over in a pool of blood outside the building with a handgun next to his body. He shot himself in the torso and head, police sources said. (Theodore Parisienne for New York Daily News) On Friday, stunned associates described how the horrific murders of a humble, hardworking man and his kind wife have had a deep impact on the community. “He was a very nice and extremely good person,” Eddy Borrero, 66, a beer wholesaler who works out of the same building, said of Ferrer. “It’s terrible,” he said. “Everybody is saying it’s terrible. Even the guys in the street are in tears.” Scene where cops found Tonatihu Rojas Lopez dead after shooting his parents, police said. (Theodore Parisienne for New York Daily News) Others recalled how Ferrer’s relationship with his stepson had seemingly taken a dark turn. An employee at Ferrer’s store said Rojas Lopez worked for his  stepdad for several years but “stopped because he had mental issues,” said the man, who didn’t give his name. “He might have had a mental breakdown.” About three months ago, friends of Ferrer began noticing that he seemed troubled by issues at home. “Francisco was down in the dumps,” said Rogelio Vargas, an employee at the beer wholesaler. “He’d say, ‘I’ve got family problems.'” Weapon used by Tonatihu Rojas Lopez, who cops say shot his mother and stepfather and then himself on Oct. 31, 2024. (Theodore Parisienne for New York Daily News) Things came to a head about two weeks ago, when Rojas Lopez walked into the business, locked the door and then had a fistfight with Ferrer, workers said. A restaurant owner on the same block said Ferrer told him he was growing distant from Rojas Lopez because he was always holed up in his room and on his computer for hours — and that the stepson had a gun. “He used to stay in his room and he will ask that no one bother him, no one speak to him, like, ‘Just don’t bother me. I’m working on something important,’ and that’s all his father knew. “He was good guy,” the owner said of Ferrer. “Him and my father … they used to just talk about life. [He] always used to tell my dad like, ‘Hey, don’t kill yourself working. It’s not worth it. Just enjoy life.’ He had plans of going back to Mexico, selling his business, because he was just tired. He just wanted to go enjoy whatever money he earned. “That was the sad part to me, I was like, what the heck? This guy was really about to go back to Mexico, just enjoy life, and then this happens? It was just really sad to me.”