A 23-year-old student from Gujarat, Om Brahmbhatt, has been arrested in the US on murder charges after he allegedly shot dead three members of his family – his grandfather Dilip Kumar Brahmbhatt (72), his grandmother Bindu and his uncleYash Brahmbhatt (38) inside a New Jersey condo on Monday. The shooting took place at a residence on Coppola Drive in South Plainfield at around 9 am (local time).The motive for the killings wasn’t known until Tuesday. Om is in custody at a correctional center in North Brunswick, media reports said. Neighbours of the family on Coppola Drive had reported hearing gunshots on Monday. Dilip and his wife moved to the US recently to live with their son, people close to the family said. Om relocated 18 months ago for higher studies.