MORGAN HILL — The FBI is joining the Santa Clara County Sheriff’s Office investigation into a July 25 shooting at a rural house party that killed an 18-year-old San Jose man and wounded six others, and is offering a $20,000 reward to stimulate tips in the case, authorities said.

The sheriff’s office announced the boost of federal resources Wednesday as investigators continue to seek the person behind the late-night shooting at a property near Hale Avenue and Miramonte Avenue in unincorporated Morgan Hill, an area tucked between fields and a mushroom farm.

Desiderio Romero V, an 18-year-old resident of San Jose and rising high school senior, was fatally shot at a party in Morgan Hill on Saturday night that also injured six others. "He was just a good kid at the wrong place at the wrong time," said his grandfather Desiderio Romero III. (Desiderio Romero III)Desiderio Romero V, an 18-year-old resident of San Jose and rising high school senior, was fatally shot at a party in Morgan Hill on Saturday night that also injured six others. “He was just a good kid at the wrong place at the wrong time,” said his grandfather Desiderio Romero III. (Desiderio Romero III)

Sheriff’s deputies were dispatched to the site around 10:15 p.m. that night for reports of intoxicated people in the street and someone throwing bottles at cars, but instead arrived to the sight of around 300 people fleeing from gunfire.

Desiderio “Desi” Romero V, who was entering his senior year in high school, died at the scene. Six other partygoers were treated for injuries at local hospitals.

The crowd had gathered for what the sheriff’s office described as a “pop-up” birthday party, and a person claiming to have planned and promoted the event on Instagram acknowledged his role and voiced remorse about the violence. There is no indication that the party had been permitted or sanctioned by any government entity.

To this point, no suspects have been identified. Sheriff Robert Jonsen said in a statement that leads exist into who was behind the shooting, and welcomed the FBI reward to incentivize getting that information to investigators.

“With hundreds of people in attendance, someone knows something,” Jonsen said. “We’ve asked for the FBI’s assistance, and we are calling on our community to help identify those responsible for this heinous crime.”

In addition to offering the $20,000 reward for information leading to an arrest in the case, the FBI established a dedicated web page for tipsters to submit information and also upload photos and video from the party: fbi.gov/morganhillshooting.

“No piece of information is too small, and your tip could make a difference in bringing justice to the victims, their families, and the Morgan Hill community,” Scott Schelble, special agent in charge for the FBI San Francisco field office, said in a statement.

Anyone with information about the July 25 shooting can submit information on the dedicated FBI website, call 1‑800‑CALL‑FBI, or contact the sheriff’s office at 408-808-4431 or by email at SHF.SOTips@shf.sccgov.org.