A Florida woman accused of firing at least 20 rounds towards Rihanna’s Los Angeles home has been indicted on 14 felony counts, including attempted murder, with prosecutors saying the singer was the intended target.

Ivanna Lisette Ortiz, 36, pleaded not guilty after a Los Angeles County grand jury indictment was unsealed on Wednesday. Her bail was set at $2.65 million and she is due back in court on 29 October, according to the district attorney’s office.

“This is a person who wanted to kill Rihanna,” Deputy District Attorney Alexander Bott told reporters outside court. “Everyone else was collateral damage.” 

The indictment charges Ortiz with one count of attempted murder, 10 counts of assault with an assault weapon and three counts of shooting at an inhabited dwelling or camper. The assault charges are more serious than the semiautomatic-firearm counts originally filed in March. 

Prosecutors allege Ortiz drove a Tesla to Rihanna’s property in Beverly Crest on 8 March and opened fire from an AR-15-style rifle, sending at least 20 rounds towards the property and a neighbouring house. No one was injured. 

Bullets struck an Airstream trailer where Rihanna and her partner, rapper A$AP Rocky, were at the time, according to a police report cited by the Associated Press. Shots also hit the outside wall of the nursery, where the couple’s three children were with their nanny. 

Rihanna’s mother and members of staff were also at the property, while Hollywood agent Tracey Jacobs was inside the neighbouring house. The 10 assault counts correspond to people who prosecutors say were present across the two properties. 

Rihanna told investigators after the shooting that she heard about 10 loud noises that sounded like something striking metal, according to the AP. She said she pulled Rocky from a bed onto the ground and later saw bullet marks on the windscreen of the trailer near where she had been standing. 

The district attorney’s office said Ortiz fled after the shooting and was arrested later in Sherman Oaks. Authorities said she was the registered owner of the rifle, which had been obtained in Florida. 

Ortiz told investigators on the day of her arrest that she was not attempting murder, according to the AP. Her lawyers have entered not-guilty pleas and have not publicly set out a detailed defence to the allegations.

Prosecutors have not established a publicly confirmed personal connection between Ortiz and Rihanna or announced a definitive motive. The AP reported that Ortiz had posted increasingly hostile comments about the singer on Facebook and YouTube in the months before the shooting, including statements authorities regarded as threatening.

The grand jury returned the indictment on 18 June, but it remained sealed while Ortiz underwent psychiatric evaluation. A judge ruled this week that she was competent to stand trial; details of the psychiatric assessments remain sealed.

The Los Angeles County District Attorney’s Office said Ortiz could face up to life in state prison if convicted on all counts. The charges remain allegations, and she is presumed innocent unless proved guilty in court.