SAN DIEGO - A Navy sailor who was allegedly carrying an assault rifle and wearing body armor when he was shot by a San Diego police officer in a downtown apartment building pleaded not guilty from his hospital bed Wednesday to a charge of exhibiting a firearm.

Esteban Nandin, 24, was ordered held on $100,000 bail.

Deputy District Attorney Robert Eacret said Nandin faces three years in prison if convicted, although the continuing investigation may yield additional charges.

Officers were called to a six-story residential unit, above commercial space and just south of Horton Plaza, shortly before 3 a.m. Sunday.

Someone inside 606 Third Ave. told a 911 dispatcher that a man wearing a tactical vest and carrying a military-style assault-type weapon was in a first-floor corridor.

Police said arriving officers entered the lobby of the building and, as one opened a stairwell door leading to the garage, spotted a man – later identified as Nandin -- with a gun.

The defendant saw the officers and allegedly began to raise the barrel of the weapon towards them. The officer closest to Nandin defensively fired two rounds from his duty weapon, striking the suspect, police said.

Nandin retreated into the stairwell and a SWAT team was called.

About 50 minutes after the shooting, Nandin -- bleeding from his chest and arm -- emerged from the building unarmed and was taken into custody.

A loaded military-style assault rifle, gas mask, handgun and a body armor vest were found in the stairwell, police said.

The officer who fired the shots was an 18-year veteran of the department, according to police.

Nandin faces upcoming surgery -- including a skin graft -- said defense attorney Jeremiah Sullivan.

The defendant is a 2nd class petty officer stationed at Coronado Amphibious Base.

Superior Court Judge Lorna Alksne scheduled a bail review for Tuesday. A readiness conference was set for Nov. 9 and a preliminary hearing for Nov. 27.