A 34-year-old Hilo man charged with murder in the fatal shootings of his girlfriend and her mother pleaded not guilty Thursday in Hilo District Court, Deputy Prosecutor Darien Nagata said.

Sean Matsumoto was charged with one count of first-degree murder, which carries a life sentence without the possibility of parole, two counts of second-degree murder and three counts of use of a firearm in a separate felony. He also faces a reckless-endangering charge for allegedly putting a minor in danger of death, police said.

Rhonda Ahu, 45, Matsu­moto’s girlfriend, and her mother, Elaine Ahu, 74, were killed Monday night at their Hilo home.

The judge denied bail for Matsu­moto. His preliminary hearing is set for 2 p.m. Tuesday in District Court.