TRENTON, N.J. — The sister of a man charged with setting off bombs in New Jersey and New York and injuring more than 30 people this month told police in August 2014 that he was getting ready to hit her with a dumbbell and stabbed another brother in the leg when he jumped in to help her, police reports show.

Zobydha Rahami told investigators that Ahmad Khan Rahami was preparing to pray when he began throwing things at her in their family’s home above their fried chicken restaurant in Elizabeth. She said he then punched and slapped her in the face, hit her and her mother with a phone charger wire and grabbed the dumbbell.

She said an ensuing fight between Ahmad Rahami and two of his brothers led to brother Nasim Rahami placing him in a chokehold before Ahmad Rahami grabbed a knife from a coffee table and stabbed him in the leg. She said the fight continued as Nasim Rahami, another brother and then Ahmad Rahami’s wife tried to get the knife away from him and then Ahmad Rahami threw a pan at him and went to his room with his wife.

Zobydha Rahami told police that she feared for her brothers’ lives but the police weren’t called that night because the siblings “did not want to get our brother in trouble.” The next day, Ahmad Rahami got into an argument with his father, who then wanted the police to arrest him, she said, according to a statement police took from her on Aug. 22, 2014.

Zobydha Rahami and Nasim Rahami were treated at a hospital for minor injuries and were released.

Ahmad Rahami, an Afghan-born U.S. citizen, spent a month in jail before his sister and brother told investigators they didn’t want to pursue charges, and a grand jury then declined to indict him.

It was after that incident that the Rahami siblings’ father, Mohammad Rahami, said he told the FBI about Ahmad Rahami’s apparent Muslim radicalization and said he had “become bad.” He said his son visited Afghanistan and Pakistan the year before and was a changed person.

A senior FBI official pushed back against Mohammad Rahami’s claim to have warned agents about his son.

FBI agents interviewed the father after the arrest because he had expressed concern to someone following that episode over his son’s internet use and some of his associates, the official said. But in interviews with agents, Mohammed Rahami “at no time” discussed his son’s radicalization or potential interest in al-Qaeda, the Taliban or their propaganda, said the FBI official, who wasn’t authorized to discuss the case by name and spoke on the condition of anonymity.

Ahmad Rahami has been hospitalized since he was caught following a shootout with police in Linden last week, days after the bombings. Officials said he remained unconscious Tuesday. He has not made an initial court appearance, and his American Civil Liberties Union lawyers declined to comment.

Rahami has been accused of detonating a pipe bomb in a New Jersey shore town and a pressure cooker bomb in New York City on Sept. 17. No one was injured in the Jersey blast, and 31 people were injured in the New York blast. A second pressure cooker bomb didn’t explode.

Associated Press writer Eric Tucker, in Washington, D.C., contributed to this story.

This story has been corrected to show the man spent a month, not more than a month, in jail before his siblings talked to investigators.