Detectives are investigating a string of shootings at a historic state park in Malibu, California, after a man was killed as he camped with his two young daughters.
Police say 35-year-old scientist Tristan Beaudette was shot in the head while inside his tent at the Malibu Creek State Park in June.
His daughters, who are aged two and four, were unhurt.
So far detectives say they have not uncovered a suspect or a motive.
Following Mr Beaudette’s death, a number of people came forward to report shootings in the area dating back almost two years.
In November 2016, James Rogers was sleeping in a hammock during a hiking trip through the park when he was struck by gunfire and required surgery.
One of the reported shootings had taken place just four days earlier.
Two more shootings were reported this week, although police have not confirmed a link between any of the incidents.
A reward for information has now reached $15,000 (£11,460).
A GoFundMe site in support of Mr Beaudette’s wife Erica and family has so far raised more than $150,000 (£114,690) in donations.
“Tristan was out doing something he adored in life, being in the outdoors with his two young girls,” supporters wrote.
“They were about to embark on a new chapter in their lives. And then it was all taken away, by a fatal gunshot in the middle of the night, in front of his two young daughters.
“Not a second goes by that we aren’t grappling with the senselessness of this crime.”
The 8,000-acre park, which attracts 300,000 visitors a year, has remained closed since Mr Beaudette’s death and police patrols have been stepped up in the area.
“Our hearts go out to the victim and his family during this difficult time,” the California State Parks Department said in a statement.
“The safety of park visitors is our priority.”
Rugged and mountainous, the park was owned for decades by 20th Century Fox and was the setting for dozens of movies including Tarzan, Planet of the Apes and the long-running TV show M*A*S*H.
The shootings are causing alarm among residents near the park.
“I’ve never so much as had a bike stolen,” Gayle Shea told the LA Daily News.
“I wouldn’t go walking there now. Would you?”