The deadly assault was reported around 7:38 p.m.in the 5300 block of Hillflower Drive, according to Livermore police.
A Livermore man was arrested in connection with the killing his 85-year-old grandmother and the injuring his mother with a kitchen knife, police said.
His mother is being treated for minor stab wounds and is expected to be released from a hospital soon, said Officer Ryan Sanchez, a spokesman for the Livermore Police Department. The suspect ran from the scene before police got to the scene.
Officers searched the area and found Haskell about a mile away from the home. He was arrested without incident.
Police do not know the motive for the stabbing, but said that Haskell suffers from multiple mental illnesses. His 62-year-old mother was hospitalized with non-life threatening injuries. Anyone with information about this case is asked to call the Livermore Police Department at 925-371-4777.