SAN LEANDRO, Calif. — Black Friday’s typical jostling and jockeying took a more ominous turn during this year’s bargain-hunting ritual with a shooting, a pepper spraying and other episodes of violence that left several people injured.

In the most serious case, a robber shot a shopper who refused to give up his purchases outside a San Leandro, Calif., Walmart store, leaving the victim hospitalized in critical but stable condition.

Police in San Leandro, about 15 miles east of San Francisco, said the victim and his family were walking to their car around 1:45 a.m. Friday when they were confronted by a group of men who demanded their shopping items. When the family refused, a fight broke out, and one of the robbers pulled a gun and shot the man, said Sgt. Mike Sobek.

“The suspects saw these guys, got out of their car and tried to rob them but were unsuccessful,” Sobek said.

At another Walmart in a wealthy suburb of Los Angeles, a woman trying to get the upper hand to buy cheap electronics unleashed pepper spray on a crowd of shoppers, causing minor injuries to 20 people, police said.

The attack took place about 10:20 p.m. Thursday shortly after doors opened for the sale at the Walmart in Porter Ranch in the San Fernando Valley.

The store had brought out a crate of discounted Xbox video game players, and a crowd had formed to wait for the unwrapping, when the woman began spraying people “in order to get an advantage,” police Sgt. Jose Valle said.

Ten people were slightly injured by the pepper spray and 10 others suffered minor bumps and bruises in the chaos, Valle said. They were treated at the scene.

The woman got away in the confusion, but could face felony battery charges if found, Valle said.

Meanwhile, police in suburban Phoenix came under fire when a video was posted online showing a 54-year-old grandfather on the floor of a Walmart store with a bloody face, after police said he was subdued Thursday night trying to shoplift during a chaotic rush for discounted video games.

The video, posted on YouTube, shows Jerald Allen Newman unconscious and bloodied as outraged customers yell expletives and say “that’s police brutality” and “he wasn’t doing anything.”

In a police report that redacted the names of officers and witnesses, Newman’s wife and other witnesses said he was just trying to help his grandson after the boy was trampled by shoppers, and only put a video game in his waistband to free his hands to help the boy.

Larry Hall, assistant chief of Buckeye police, said Newman was resisting arrest and it appeared the officer acted within reason.