WATCH: Knife-wielding suspect slashes employee amid stabbing spree that killed 4, injured 2 [GRAPHIC video]

Authorities in California released graphic surveillance footage showing part of Wednesday’s stabbing spree that left four people dead and two others wounded.

Zachary Castaneda, 33, allegedly burglarized his neighbor’s apartment then traveled two miles away to a bakery, where he took off with their cash register. Castaneda circled back to his neighbor’s apartment to stab the neighbor, identified as Helmuth Hauprich, 62, and his roommate to death, according to the Los Angeles Times.

The stabbing and robbery rampage which terrorized Santa Ana and Garden Grove lasted two hours. Garden Grove police said surveillance cameras caught many of the attacks.

On Thursday, police released footage apparently showing Castaneda slashing a female employee at Best One Insurance Agency amid an attempted robbery.

***WARNING: The video below contains violence which could be disturbing to some viewers. Please use discretion.***

How do you protect your children from predators? Join Nancy Grace and a team of world-class experts for the online course ‘Justice Nation: Crime Stops Here’.

The video shows the employee sitting at a desk when Castaneda, who’s wearing a dark hooded sweatshirt, allegedly approaches her while wielding two knives. He swings the knives at her in rapid succession as the woman cowers behind the desk.

The woman later attempted to flee and placed chairs between herself and the assailant. The suspect briefly looked around the business before appearing to grab something and storming out.

In addition to the female employee, authorities said a man nearly had his nose severed by Castaneda as the suspect filled his tank at a Chevron gas station. After killing his neighbor and his roommate, he reportedly entered Cash N More and robbed a customer.

Cash N More employee Yesenia Torres, 34, told the Los Angeles Times that she had just processed a $200 loan for the female customer when Castaneda told her to hand over the money. Torres said she didn’t see him brandish a weapon.

The rampage concluded in Santa Ana at around 6:30 p.m. Moments earlier, Castaneda allegedly stabbed Pascual Rioja Lorenzo, 39, to death near a Subway restaurant. He reportedly crossed the street to a 7-Eleven to fatally stab security guard Robert Parker, 58, and take his gun.

According to NBC News, undercover officers spotted Castaneda outside the 7-Eleven wielding a knife and gun. They ordered him to drop the weapons and took him into custody.

“He remained violent with us through the night. He never told us why he did this,” Garden Grove police Lieutenant Carl Whitney said.

While authorities haven’t pinpointed a motive, Whitney said Castaneda was driven by “robbery, hate, [and] homicide.” Days before the stabbing spree, Castaneda’s wife had filed documents to move on with their divorce, according to the Los Angeles Times.

“There was no indication this was a hate crime,” Whitney said, according to The Orange County Register.

“We just know this was a random act of violence and the guy unleashed evil across our two cities.”

Castaneda was said to be a known gang member. Garden Grove police Chief Tom DaRe described him to reporters as a “violent individual” who’s been incarcerated 14 times since 2016. DaRe attributed his short prison sentences to Assembly Bill 109, a state bill intended to resolve prison overpopulation.

Castaneda’s rap sheet goes back to 2004. On July 22, he pleaded not guilty to a felony charge of carrying a knife in addition to drug possession and driving on a suspended license, court documents obtained by KCBS stated.

Castaneda remains jailed on $1 million bail.

For the latest true crime and justice news, subscribe to the ‘Crime Stories with Nancy Grace’ podcast.

Join Nancy Grace for her new online video series designed to help you protect what you love most – your children.

[Featured image: Zachary Castaneda/Garden Grove Police Department]