SAN FRANCISCO (CBS SF) — The suspect in the brutal assault that fatally injured an 84-year-old San Francisco resident last week entered a not guilty plea to a homicide charge during a court appearance Wednesday.

It was the first court appearance of 19-year-old Daly City resident Antoine Watson since he was arrested for the assault this past weekend.

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Watson entered a not guilty plea to charges of murder and elder abuse causing death during the brief court appearance. As he was escorted out of the courtroom, an older woman later identified as his grandmother shouted, “I love you Antoine!”

When asked outside the courtroom what she wanted to see happen, Watson’s grandmother said, “To see him walk out this door like I’m walking out right now.”

84-year-old San Francisco resident Vicha Ratanapakdee was the target of the brazen and unprovoked daytime attack last Thursday morning.

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Surveillance video from a camera across the street captured the moment of impact.

Ratanapakdee is seen walking in the driveway of a home when the suspect barrels him into the victim violently, knocking him to the ground before the suspect casually walks away in the same direction he came from.

San Francisco police were quickly able to identify Watson as the assault suspect.

According to the San Francisco District Attorney’s office, Watson had been observed and contacted by San Francisco Police officers earlier that Thursday morning for traffic infractions resulting in a minor collision. Police officers issued him a citation.

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Patrol officers’ body camera footage of the encounter led officers to later identify Watson as the suspect in the murder of Ratanapakdee. They also identified a female associate he was with at the time of the assault as 20-year-old Daly City resident Maylasia Goo.

Saturday evening at approximately 8:45 p.m., officers served a search warrant on the 500 block of Lisbon Street in Daly City and located Watson and Goo, who were arrested without incident.

Tuesday morning, San Francisco Mayor London Breed, Police Chief Bill Scott and District Attorney Chesa Boudin denounced the recent rise in violent crimes in the city, particularly the fatal assaults on Ratanapakdee and 76-year-old private investigator Jack Palladino.

Breed spoke of the shock she felt seeing the brutal assault of Ratanapakdee on video and offered her sympathies to the family.

“I can’t even imagine what his family is going through right now. It was heartbreaking. And the fact that another human being would do that to an elderly senior in our community is one of the most disgusting things I’ve ever seen,” said the mayor.

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Breed went on to say that she was appearing with both Chief Scott and District Attorney Boudin to say that violence in San Francisco would not be tolerated and that any perpetrators would “be held accountable to the fullest extent of the law,” especially those who targeted children or the elderly.

“Look, I believe in second chances. I believe people are better than the worst things they have done,” said Breed. “But when you cross that line, when you commit murder, when you take someone’s life like that, we as a city and as a society have to hold you accountable for your actions. And you have to take responsibility for the pain and the suffering you caused.”

Breed said that she had the support of both the police department and the District Attorney’s office in her stance.

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“You will be held accountable by both the police and the District Attorney. There will be consequences. Let’s dispel the myth right now that there are no consequences for committing crimes in San Francisco,” Breed said.