Joshua Waring, the son of former "Real Housewives of Orange County" star Lauri Peterson, did not have gunshot residue on his hands or clothing after his arrest in connection with an attempted murder, according to an analysis performed by the Los Angeles County Department of Medical Examiner-Coroner.
Forensic experts cautioned against drawing the conclusion that the analysis supported Waring's claim that the results could exonerate him.
Waring, 28, has been in an Orange County jail for 10 months in connection with a drive-by shooting in June that left a man severely injured.
Waring said during a jailhouse interview last week that the results of the residue test — performed to help determine whether a suspect had recently fired a gun — could clear him. Waring received the results Monday.
However, Debra Gibson, acting chief of forensics laboratories for the Los Angeles County coroner's office, wrote in the report that the findings were inconclusive.
Michael Martinez, a forensic scientist supervisor at the Bexar County Criminal Investigation Laboratory in Texas, said Thursday that "gunshot residue is nothing more than an investigatory tool."
"Getting an exoneration because gunshot residue can't be found is a huge leap," Martinez said in a phone interview.
The Orange County district attorney's office declined to comment about the results.
According to experts, there are a variety of reasons that residue might not be found on a person's hands even if he or she had fired a gun.
The person could have been wearing gloves, washed or wiped his or her hands or otherwise caused the particles to become dislodged, according to the report and Martinez.
The type and caliber of the gun used can play a role in how much residue is left behind, Martinez said, as can the amount of time between the shooting and when the sample was collected. Martinez said the ideal window for collecting gunshot residue is within four to six hours after a gun is fired.
"That doesn't mean we can't find any … after six hours," Martinez said. "It just means that's the window where it's most likely to be found."
Waring was arrested about eight hours after the shooting.
Authorities have alleged that he showed up at a Costa Mesa house in a BMW around 2:30 a.m. June 20 and fired shots at three people outside. One man was injured.
An Orange County Sheriff's Department helicopter crew located the BMW, and police followed it through Santa Ana before it crashed into another vehicle, authorities said.
Santa Ana police said in court that Waring ran and hid in the restroom of a nearby business before surrendering to officers.
During a preliminary hearing last year, Waring told Orange County Superior Court Judge W. Michael Hayes that he fled from police because he was heading to pick up drugs.
Waring faces three counts of attempted murder, one count of unlawfully discharging a firearm at an inhabited dwelling, three counts of assault with a firearm, one count of vehicle theft, one count of shooting at another person from a motor vehicle and one count of evading police while driving recklessly, all felonies.
He also faces misdemeanor charges of battery, resisting an officer, and hit-and-run with property damage, along with possible sentencing enhancements on allegations of personal use of a firearm and inflicting great bodily injury.
If he's convicted at trial, Waring could be sentenced to life in prison.
He is due back in court for a pretrial hearing June 14.