A 21-year-old man is being held after striking a rookie police officer in the head with a baseball bat and stealing his gun in Queens early yesterday morning, police and court officials said. The maximum sentence for such an offense is 25 years.

Just two months out of the police academy, Officer Joseph Cho, 32, was on foot patrol in the Jackson Heights section of Queens when Danny Fernandez came upon him from behind and hit him with a bat, police said. Another officer on foot patrol, Patrick Lynch, 22, observed Mr. Fernandez strike Officer Cho again while he was on the ground. Mr. Fernandez then sprinted off with his service weapon and handcuffs, police said.

The attack occurred near the corner of 102nd Street and 39th Avenue, police said.

Officer Lynch chased Mr. Fernandez and arrested him with the assistance of Officer Christine Schmidt, 26. Officer Cho’s gun was found on Mr. Fernandez, police said.

Officer Cho was rushed to Elmhurst Hospital, where he was initially listed in serious condition. Yesterday afternoon he was upgraded to stable condition. He required several stitches on the back of his head, a hospital spokeswoman said.

The Queens district attorney, Richard Brown, said Mr. Fernandez’s attack, which he described as premeditated, was “for the apparent purpose of stealing his weapon so that he might use it to commit future armed robberies.”

“It is a miracle that the officer survived,” Mr. Brown said.

Police charged Mr. Fernandez, who has five prior arrests for summonses, with attempted murder of a police officer, assault in the first degree, robbery in the second degree, criminal possession of a weapon in the second, third, and fourth degrees, and criminal possession of stolen property. For the first and most serious charge, he faces up to 25 years in prison, the Queens district attorney’s office said.

“The outstanding response by these young officers to this vicious attack on their fellow officer prevented the assailant from escaping and posing an even greater risk to the public,” the police commissioner, Raymond Kelly, said.

On his way back to the city from Albany, Mayor Bloomberg visited Officer Cho in his hospital room.

A husband and wife who live with the Fernandez family at 78–18 162nd St. described Mr. Hernandez as a quiet young man who wasn’t often in trouble.

Speaking through a translator, Carlos Garcia said: “He is a calm kid. He hasn’t had any problems in the past that I’ve known of. He works hard. He is gone from 5 a.m. to 6 p.m.”

It was not clear yesterday where Mr. Fernandez worked.

Officer Cho graduated from the police academy December 26. Traditionally, new recruits are sent in large numbers to patrol high-crime areas after they leave the academy.