SAN ANTONIO, Texas (CN) – A police officer for a Texas school district may have used excessive force in fatally shooting a teenager who fled the scene of a fistfight, a federal judge ruled.

Denys Lopez Moreno sued Officer Daniel Alvarado, Police Chief John Page and the Northside Independent School District in September 2011 for the death of her 14-year-old son, Derek Lopez.

The incident unfolded on Nov. 12, 2010, when Lopez allegedly exited a school bus and, in view of Alvardo, punched another student.

Lopez ignored Alvarado's order to freeze and fled the scene with the school officer tailing him in a patrol car, according to the amended complaint.

With Lopez hiding in a shed at a nearby home, Alvarado drove back to the scene of the fight but allegedly refused to give up the search.

"Ignoring his supervisor's orders to 'stay with the victim and get the information from him,' Alvarado placed the second boy into the patrol car and sped into the neighborhood to search for Derek," the complaint states.

Local homeowners then directed Alvarado to the shed, Moreno claimed.

"In violation of NISD police department procedures, Alvarado drew his weapon immediately after exiting the patrol car," the complaint states. "With his gun drawn, he rushed through the gate and into the back yard. Within seconds from arriving at the residence, Alvarado shot and killed the unarmed boy hiding in the shed."

Moreno said the officer had a history of disregarding orders.

"In approximately a four (4) year period leading up to the shooting, defendant Alvarado had been reprimanded sixteen (16) times," according to the complaint. "Specifically, he had been reprimanded for insubordination and failure to follow supervisors' directives seven (7) times. Due to his poor service record, Alvarado was suspended without pay on five (5) occasions. On May 21, 2008, Alvarado was recommended for termination by Page. Despite being recommended for termination for insubordination and for refusal to follow supervisor directives, Alvarado remained on the force without remedial training."

U.S. District Judge Xavier Rodriguez granted the school district and Page summary judgment on Friday, but he refused to dismiss the claims of excessive force and negligence against Alvarado.

"In this case Alvarado testified that he saw an individual (later identified as Derek) strike another (later identified as Chris Avilez) about three times at a bus stop," the orderstates (parentheses and brackets in original). "He testified that he thought a misdemeanor assault had taken place. He placed the victim in his patrol car. A fact issue exists as to whether Alvarado was able to determine Derek's age and the age of the victim, while that person was in his patrol car. When Alvarado arrived at the house where the shed was located, Alvarado testified that Derek posed no threat to the homeowner; that if he thought Derek was violent it would have been prudent for him to wait for backup; that at the moment he unholstered his weapon Derek posed no threat to him; and he drew his weapon because he thought that Derek could pose a threat by using some object in the shed as a weapon. Alvarado testified that at no time did he see Derek with any gun or knife. Alvarado further testified that after the shed door hit his face, he 'felt that [Derek] was coming after me, so I – I took the shot.' Alvarado never saw Derek grab for any weapon.

"An officer cannot use deadly force without an immediate serious threat to himself or others. Here, genuine issues of material fact exist as to whether there was such an immediate threat."

Northside ISD is the fourth largest district in Texas and encompasses the northwest section of San Antonio, according to its website.

The school district attracted national attention last year when a father challenged its program for tracking students with chip-embedded identification badges. The San Antonio Express-News reported on Monday that the district has ditched the program.