OCEANSIDE -- Gregory Kwok, the 48-year-old man shot Sunday at his Lonnie Street home during a confrontation with Oceanside police, remains under guard at a La Jolla hospital.

Kwok's detention by police for more than three days even though no charges have been filed against him is being questioned by the critically injured man's father and a public defender.

"If he has been under arrest since Sunday and no charges have been filed, he should no longer be in police custody," Deputy Public Defender Gary Nichols said Wednesday.

Aubrey Kwok, Greg Kwok's 81-year-old father, said Tuesday that police told him he couldn't visit his son at Scripps Memorial Hospital in La Jolla because of an open investigation.

District attorney's office spokesman Steve Walker said the office has not filed charges against Kwok in part because it has not received the case from Oceanside police. It is unclear what charges Kwok would face.

Walker said if Kwok were charged, his arraignment would be delayed because he is incapacitated and cannot answer any charges.

But Nichols said the district attorney's office could file the complaint against Kwok even if he was incapacitated.

Kwok, a mechanic who lives with his father in a small home near MiraCosta College, was shot by police Sunday when he allegedly ignored their commands to stop advancing and grabbed at an officer's gun.

Police had been called to his house after neighbors reported that Kwok was fighting loudly with his father and had fired a gun into the ground in his front yard.

Nichols said that generally, the law says a prisoner can only be kept in custody for 48 hours without being charged. Without charges, Kwok should no longer be under arrest and should be free to receive visitors, he said.

Sgt. Kelan Poorman said that Kwok's room at Scripps Memorial Hospital in La Jolla was under 24-hour guard by an Oceanside police officer and would probably be guarded until an arraignment.

Midday Wednesday, Poorman said that no visitors would be allowed until Kwok was arraigned. But later in the day, Poorman said police had decided that close family could visit.

He said because of Kwok's unusual circumstances, the normal timeline for arrest, charging and arraignment don't apply.

"Normally, he would have been arraigned by now, and once there was that arraignment, he would have been formally in custody," Poorman said. Once in custody, it would be up to the San Diego County Sheriff's Department, which runs the county's jails, to guard him and schedule visitations.

According to hospital spokeswoman Lisa Ohmstede, the Sheriff's Department routinely allows visitors to request a hospital visitor's pass in court.

Contact staff writer Sarah Gordon at (760) 740-3517 or sgordon@nctimes.com.