SAN FRANCISCO (CBS SF) — Police in San Francisco on Monday asked for witnesses to an assault near Dolores Park earlier in July that left a male victim hospitalized with life-threatening injuries to step forward.

In a release issued by the San Francisco Police Department, authorities said that on the evening of Sunday, July 12, a woman came to the Mission Station and reported an assault on her boyfriend that had happened several days earlier on Thursday, July 9.

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The woman said she and her boyfriend were in the area of 19th and Dolores Streets during the “Dolores Park Hill Bomb” skateboarding event when they had an argument. She said that as she began to walk away from him, she turned around and saw an unknown suspect punch her boyfriend in the face.

The victim, a 32-year-old male, fell to the ground and hit his head, losing consciousness. The victim was transported to an area hospital with life-threatening injuries where he currently remains.

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Investigators from the Mission Station took over the case, which led to the identification of 25-year-old Stockton resident Rogelio Lupian Jr. as a suspect in the assault. On Friday, July 17, officers from Mission Station officers responded to Dolores Park and located Lupian.

The suspect was taken into custody without incident and booked at San Francisco County Jail on charges of assault by means likely to produce great bodily injury and aggravated battery causing serious bodily injury.

While a suspect was arrested in the case, police said the investigation remains open as authorities seek additional witnesses to the July 9 incident. Police released a series of photos from the night in question showing people who were at the scene and may be able to provide more information.

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Dolores Park assault possible witnesses (SFPD)

Police investigators are asking the potential witnesses shown in the photos, any other possible witnesses to the incident or anyone who knows someone who may have seen the assault to please contact investigators. The SFPD can be reached via the tip line at 1-415- 575- 4444 or Text a Tip to TIP411 and begin the text message with SFPD. Anyone contacting police may remain anonymous.