(CNN) A neighbor's doorbell camera caught a man assaulting and dragging his ex-girlfriend, who was later found being held against her will in a Southern California home, police said.

Robert Michael Mendez, 27, faces charges including suspicion of attempted murder, kidnapping and false imprisonment after the Arcadia Police Department on Monday received a video link to the doorbell camera, the department said in a news release. The timing of his first court appearance and whether he has an attorney weren't clear Wednesday.

The video, which police believe is from late Sunday night, shows a woman running and pounding on a neighbor's door when a man grabs her by the hair and drags her to the lawn, according to the footage, obtained by CNN affiliate KCAL/KCBS

The video is stamped with the logo of Ring, the Amazon-owned company that works with more than 400 police departments nationwide, including Arcadia's . Police can request videos to help with active investigations. While Ring says its police partnerships make people safer, privacy advocates warn they could create a 24/7 surveillance environment.

"I thought she was going to die," Arcadia neighbor Tammy Raycraft told KCAL/KCBS, adding that she saw the man stomping on the woman. "It was really traumatic to watch."

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