A man is in custody after killing a bird who had been beloved by locals with a rock.

Jeremy Jansen, a 36-year-old from Los Angeles, was filmed committing the unsettling act last month.

It happened at Lake Gregory near the San Bernardino Mountains, where the Great Egret known as ‘Arthur’ would regularly visit.

The same bird is seen being stoned to death in the footage, which ultimately led to the man’s arrest.

It shows him hurling a rock at the animal as it stands helpless dozens of yards away, first missing as others looked on horrified.

Even as onlookers told him to stop, he hurled a second one – this one making contact.

The bird is then seen falling into the water before being pulled out and left to die by a person with Jansen’s group. 

The event left witnesses like Kaylyn Donica in complete disbelief, as Jansen now faces animal cruelty charges.

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‘It was just shock and anger, like, “What the hell is wrong with you?”‘ Donica said of the moment in an interview with KTLA.

‘He went walking up toward the grass with it and was looking at it under its wing,’ she added of the friend who pulled out the fatally injured animal.

‘Something needs to happen. He needs to have repercussions,’ she said of the suspect, who was tracked down thanks to the cellphone video she recorded.

‘You don’t just go around and do whatever you want.’

The footage, filmed on October 23, had circulated in Jansen’s neighborhood, cops said this week.

As a result, detectives there were able to make contact with him, confirming he was the culprit responsible.

Deputies in the posh LA suburb known as Claremont proceeded to arrest and book Jansen – for animal cruelty and for violating the Fish and Game Code. 

The arrest was made Tuesday, the San Bernardino County Sheriff’s Department confirmed – not releasing a mug shot of the suspect.

The disturbing clip filmed by Donica, meanwhile, continues to gain traction online – horrifying onlookers far and wide.

“It’s just made me absolutely sick to my stomach,” resident Shyann Swisher told CBS News in early November after seeing the clip.

“This bird was a part of our community,’ she continued, her voice rife with emotion.

‘His name was Arthur.’

In an exchange with KTLA, a wildlife expert confirmed the bird seen in the footage and Arthur, a regular at the lake, were one and the same.

His death, moreover, was not a quick one, officials said – indicating how the bird was first wounded by the barrage, before ultimately dying.

‘The one guy stood up and says, “Look, a crane,”‘ Donica recalled of what predated the series of stone-throws.

As for Jansen, he was booked at the West Valley Detention Center for animal cruelty and killing a nongame bird on Tuesday. Records did not immediately indicate he’s been released. 

His alleged crimes carry a maximum three year-sentence in a state prison, a fine of up to $20,000.

DailyMail.com has reached out to the San Bernardino Sheriff’s Office for more information.