Fresno's police chief says it doesn't appear the suspect who fatally shot three people is connected to terrorism despite the statement that he made.
He then shot at another and missed, but hit a 37-year-old man walking on a pavement as he carried groceries.
So far this year, there have been more than 17,700 incidents involving guns nationwide and 4,405 fatalities, Gun Violence Archive, a not-for-profit group, said on its website.
Muhammad faces at least four counts of murder. Dyer said Muhammad had been identified quickly as the prime suspect in the Motel 6 shooting on April 13 and that police had been urgently seeking him across the Fresno area since then.
The driver of the truck sped off to the police department for help.
Muhammad went by the nickname "Black Jesus" and has made posts against white people and the government on his Facebook page, Fox News reported.
Police are searching for the revolver Muhammad said he threw into a pile of clothing.
A psychiatrist who examined Muhammad believed he had psychosis, his lawyer said in the court filing. A Catholic Charities spokesperson said there does not appear to be any connection between the shooter and Catholic Charities, the Fresno Bee reported. A flurry of posts emerged in the past day.
"We do not believe. that this is a terrorist-related crime", Dyer told reporters.
A posting Monday says, "My kill rate increases tremendously on the other side".
According to Dyer, Muhammad surrendered to officers at the scene. Muhammad was known for criminal threats and also faced charges of forgery, false imprisonment and drunk driving.
Federal court records show Muhammad was charged in 2005 with possessing cocaine with intent to distribute. He was also indicted for possession of a firearm for drug trafficking, and possession of a firearm by a convicted felon.
Dyer says police have called the FBI to assist in the investigation.
He claimed insanity, and his attorney requested a psychiatric examination for his client, saying Muhammad "appeared eccentric with some freakish beliefs".
His lawyer said Muhammad had "paranoia" and thought the justice system and his defence were conspiring against him, court papers said.
The attorney who represented Muhammad in that case did not return a call for comment Tuesday.
Muhammad's grandmother, Glenestene Taylor, said that he'd been acting strangely when he visited her on Sunday, and that he was crying but that she said she didn't get the impression that her grandson held hatred towards any race. Muhammad has been charged in 9 criminal cases in Sacramento alone dating back to 1997.
"Immediately upon seeing me, he made a spontaneous statement saying, 'I'm sorry chief, ' then was placed in the back of the vehicle". She hung up the phone before giving her name.
"We're kind of shocked and surprised for what happened", Ghazvini said.