A maintenance worker in Texas was checking frozen or broken pipes at an apartment complex on Christmas Eve when he was fatally shot by a resident who mistook him for a burglar, police said.

Cesar Montelongo Sr., 53, was on a balcony when a shooter fired from a window seriously wounded him, Grand Prairie police said in a statement Monday.

The shooting happened around 6 p.m. Saturday at an apartment complex in the 2900 block of Alouette Drive. Montelongo was pronounced dead at a hospital, police said.

Cesar Montelongo, center, a maintenance worker, was fatally shot on the job the day before their 29th wedding anniversary.via GoFundMe

“Detectives determined that the victim was checking multiple balconies for frozen and broken water lines after multiple pipes burst,” police said. «The resident, who believed his apartment was being burglarized, armed himself with a firearm and shot the victim through a window.»

Police also said: “The resident remained on the scene and is cooperating with detectives. At this time, no arrests have been made.»

Cesar Montelongo Jr., 28, of Arlington, said Wednesday that his father was the maintenance manager at the Clayton Pointe complex in Grand Prairie, a Dallas suburb, where he was fatally shot.

“I came to find out that it was not just one bullet that was fired, but four,” he said. “He wasn’t doing anything malicious. He wasn’t even trying to open the balcony door. He wasn’t trying to get into the apartment. My dad was employed there for 16 years. All the residents knew him, and he also knew all the residents.»

The Tarrant County Medical Examiner’s Office said Montelongo Sr. died of a gunshot wound to the chest and ruled his death a homicide.

NBC Dallas-Fort Worth reported that defense attorney Russell Wilson, a former prosecutor who is not associated with the case, said the Castle Doctrine, a law that allows property owners to defend their property, in this case against anticipated theft, could apply in the shooting. Wilson said the property can extend to the balcony.

The bigger question, however, is whether the resident was notified that there would be maintenance work on their property, Wilson said. He said the response «would play a very important role,» the station reported.

No one with Clayton Pointe could immediately be reached for comment Wednesday.

Montelongo Jr. said his father was on call on Christmas Eve, which was the day before their 29th wedding anniversary. Montelongo Jr. is the eldest of the five children left behind by his father.

Montelongo Jr. described his father as «selfless» and said he preferred to live life smiling.

«Wherever I walked, it was just a light,» he said. «He always had a smile on his face. He didn’t like to be upset. He was someone who would never want to hurt anyone.»

Montelongo Jr. said his mother was «devastated» noting that she «never made it home for the anniversary.»

Montelongo Jr. also said his father’s shooting could have been «100%» prevented, but he is trying to keep things in perspective.

“We have been praying a lot and trying to find peace between us as a family,” he said. “Believing in the Lord, we forgive the person who did it. As for what’s to come, that will be determined by a grand jury and the good Lord himself.»