LOS ANGELES, Calif. — A grand jury indictment unsealed today charges a man with murdering two women and one man and injuring two other people during a shooting spree last October at a business and a home in Downey.

Jade Douglas Harris, 30, pleaded not guilty in Los Angeles Superior Court to 10 felony counts, including three counts of murder, two counts of attempted murder, four counts of kidnapping for carjacking and one count of being a felon with a firearm.

The indictment supersedes an earlier case in which Harris had been awaiting trial in connection with the Oct. 24, 2012, crimes.

The murder charges involve the slayings of Josimar Rojas, 26, Irene Cardenas Reyes, 35, and Susana Perez Ruelas, 34.

Harris allegedly went to United States Fire Protection in the 8700 block of Cleta Street about 8:45 a.m. Oct. 24 in response to an online advertisement for a car for sale.

An attorney and spokeswoman for the family said earlier that the suspect had offered to pay $25,000 in cash for the 2010 Chevrolet Camaro, but when he showed up at the business, he pulled out a gun and demanded the car.

When he learned the car was a few blocks away at the family’s home, he allegedly opened fire, killing Rojas and Reyes, according to police and prosecutors. Another woman was seriously wounded.

Harris then allegedly forced Ruelas, 34, to drive him and her 13-year-old son to the home where the car was located.

Family spokeswoman Martha Zerehi alleged that once they arrived there, the man put a gun to the boy’s head and threatened to kill him. Perez Ruelas tried to push the gun away, prompting the suspect to fatally shoot her, then shoot the boy, who played dead, authorities said.

The suspect drove off in the black Camaro, which was later recovered in Los Angeles, police said.

The teen was wounded but survived and was released from a hospital and returned to his family.

The murder charges include the special circumstance allegations of multiple murders, murder during the commission of a burglary, murder during the commission of a carjacking and murder during the commission of kidnapping.

Prosecutors have yet to decide whether to seek the death penalty against Harris, who is set to make his next appearance June 27 in Norwalk Superior Court.