A young man stood up in Long Beach Superior Court and stared through a glass partition at the man accused of killing his mother.

“I just want him to look at me,” he said as the bailiff yelled at him to sit down.

The man behind the glass, John Osborne, stood wide-eyed, his wrists handcuffed in front of him during his first court appearance Thursday afternoon.

Osborne, 31, is charged with murdering Nancy Romero, a 46-year-old Long Beach woman he’d been dating. Police called the slaying an “isolated incident of domestic violence.”

The couple’s roommates saw Osborne and Romero arguing the night of July 10, Deputy District Attorney Kelly Kelley said. The next morning, Romero was found lying on a Downtown Long Beach sidewalk with a gunshot wound in her back, according to the Los Angeles County Coroner’s office.

Kelley said investigators have security camera video showing the couple together shortly before the killing, although they don’t have the actual shooting on tape.

Romero died after being rushed to the hospital around 8 a.m. July 11.

She was found on Magnolia Avenue near Third Street, about a block from Osborne’s home on Daisy Avenue and less than a block from the courthouse where he now stood.

It wasn’t clear yet what Osborne and Romero were arguing about, Kelley said. It didn’t appear the two were in any kind of long-term relationship, she added.

When SWAT officers searched Osborne’s home the day of the killing, they found several guns registered to Osborne, but they didn’t find him, according to authorities.

Osborne turned himself in at the Long Beach police headquarters five days later, police said.

His attorney, Alex Mendoza, said Osborne walked into the station and gave up because he’s a “straight-up guy.” Mendoza said it was too early to discuss any details of the case.

Osborne now faces a maximum of 50 years to life in prison if he’s convicted on the murder charge with a sentencing enhancement for using a firearm.

“The guy killed my mom,” Romero’s son protested as the judge and bailiff instructed him to sit down or be thrown out of the courtroom.

Eventually, he took a seat on a bench along the back wall and was allowed to continue watching the proceedings. He and his family declined to talk after the hearing, saying the incident was too fresh.

Osborne is being held in lieu of $3 million bail.