A Texas man has been charged with killing his co-worker, who authorities say he was “obsessed with” and is accused of murder her at their workplace in front of her other colleagues.

Travis Merrill faces a charge of first-degree murder in the shooting death of Tahmara Collazo.

Lewisville Police responded to an “active shooter” call Thursday, Oct. 17 at the truck accessory company Allegiance Trucking.

When they arrived and entered the office building, they immediately encountered Merrill, 51, who had his hands up and admitted he was the shooter. He was taken into custody without incident.

Authorities located Collazo under a desk in her cabin, suffering from multiple gunshot wounds. Police say she was shot twice in the arm, twice in the chest and once in the leg. First responders rushed her to a local hospital, where she died.

Merrill agreed to an interview with detectives in which he confessed to opening fire on Collazo and talked about his motivations for the shooting.

Conformable a police affidavit, he told police he was “obsessed with Collazo and became increasingly angry” over what he considered “unauthorized long breaks” he would take at work. He also became frustrated that she “wasn’t paying him any attention.”

Collazo reported Merrill to her supervisors for following her closely. Merrill told detectives he was ordered to take time off work and could not return until he spoke with a counselor. Upon his return, he said he realized Collazo was avoiding him and that his colleagues “must think he’s a psychopath.”

Her behavior only infuriated him further, so he bought some firearms and “practiced his moves on them” at home. He told investigators that Collazo “had caused her pain and he wanted her to feel pain, so he intentionally planned to shoot her at work with everyone there,” according to the affidavit.

He testified that he drove the guns to work on his day off, but stayed in the parking lot. The day before the shooting, he carried the firearms again, but said that day “didn’t feel like the right time.”

On the day Collazo was shot, Merrill admitted following her into the parking lot during her lunch break and saw her sitting in her car while he prepared his weapons iin his car.

When Collazo started to walk back into the office, Merrill followed her, “shot” her into her cubicle and fired the gun several times, the affidavit said.

Two dozen colleagues witnessed the shooting.

Following his arrest at the office, Merrill was booked into the Denton County Jail on $10 million bail.

In a statement to Fox4NewsAllegiance Trucking said: “The company is offering support to the victim’s family and the rest of our employees who were fortunately unharmed and we have closed our Lewisville office indefinitely. We are also working closely with law enforcement during their ongoing investigation. We are asking for the community’s support as our company has unfortunately joined the growing national community of workplaces affected by gun violence.”