At a news conference, Police Chief Philip Sanchez said the caller, Oscar Carrillo of Pasadena, was arrested for involuntary manslaughter of Kendrec McDade.
On Saturday night, Carrillo told police that two African-American males approached him at a taco stand and asked him to buy them food. Carrillo said he refused, then looked over to see one of them stealing a backpack and laptop from his car while the other was on the lookout.
Carrillo reported to the 911 dispatcher that the suspects pointed a gun at him and then took off. Sanchez said Carrillo made up the part about the gun apparently to speed up police response time.
When responding officers arrived, they confronted the victim McDade and a 17-year-old boy he was with. McDade allegedly reached for his waist and officers, who believed he was reaching for a gun as reported by Carrillo, opened fire.
"By my account, there were several times that Mr. Carrillo emphatically indicated there was a gun involved in the initial incident. That's important. It sets the platform for the mindset of the responding officers as they pursued McDade," Sanchez said.
No weapon has been found. Police said they do not believe McDade or the other teens was armed.
However, police said they have reviewed surveillance video from the restaurant beside the taco stand that allegedly shows McDade and the other suspect involved in a theft.
The family's attorney, as well as community activists, said they have serious questions about the deadly shooting. The Pasadena Police Department has asked the Office of Independent Review to investigate the shooting, as well the Los Angeles County District Attorney's Office's officer-involved shooting team.
The two officers were on paid administrative leave. They have not been identified.
The 17-year-old suspect who was allegedly with McDade at the time has been charged with three felony counts against a minor, two for commercial burglary and one for grand theft.
No backpack or laptop was found.
The family of Kendrec McDade has set up a memorial fund at Chase: Bank Account No. 452408953.