A man suspected of shooting an active-duty Navy sailor, who stopped to help what he believed was a stranded driver in Mountain View, pleaded not guilty in court Wednesday.
Brandon Acuna, 21, was charged with first-degree murder in connection with the shooting death of 21-year-old Curtis Adams.
He was also charged in connection to a shooting and burglary 10 minutes earlier in Mount Hope, police said.
The judge did not set bail.
Early Saturday morning, Acuna was in a stopped car on the northbound Interstate 5 on-ramp when he was spotted by Adams, who believed Acuna was stranded and turned around to help, according to the San Diego Sheriff's Department.
When Adams got out of his car and approached the stranded vehicle, he was shot, Lt. Anthony Dupree said. Adams' girlfriend, whom he was with at the time, called 911.
Adams was taken to UC San Diego Medical Center where he died.
In the Mount Hope shooting, Acuna allegedly shot at a man who interrupted his attempt to break into the man's car, according to police.
Acuna was arrested after the vehicle he was in was spotted by CHP.
Acuna has a long criminal history dating back to 2015 when he was 18 years old, according to court records.
Records reveal Acuna has a history of misdemeanor offenses and show he was fined and sentenced to three years probation on Sept. 7, just six weeks before the fatal shooting.
In July, Acuna pleaded guilty to creating a public nuisance. Last year, he pleaded guilty to misdemeanor possession of methamphetamine.
And in September 2015, he admitted he had driven on a suspended license, as part of a plea bargain in which prosecutors dropped a second charge of driving without a license.
Each of those guilty pleas carried a three-year probation term, and fines totaling $1,450.
Investigators were still working to determine what led to the deadly shooting and burglary shooting. On Tuesday, SDPD said they were looking into whether more people were involved in Adams' death.
The news of Adams' death spread quickly to his hometown of Brooklyn, New York and one person close to the Navy sailor told NBC 7 he had a "heart of gold."
Acuna is expected to return to court on November 14.
Anyone with information about the incidents was urged to call the Homicide Unit at (619) 531-2293 or Crime Stoppers at (888) 580-8477.