Baltimore Police on Monday arrested a man in connection to a shooting and standoff at the Light Street Animal Hospital building, which caused nearby Thomas Johnson Elementary Middle School to go into lockdown on the first day of school.

Police were called at 9:04 a.m. to the building on Light Street near East Randall Street for a report of a shooting.

A witness to the shooting identified the victim as Dr. John Trujillo, or “Dr. T,” a beloved local veterinarian. She said his brother — who was recently fired from the animal hospital and had been served notice of eviction from an apartment in the building — shot him after a brief argument.

Law enforcement said they found the victim inside a residence in the building. Paramedics were able to get the man out while the gunman was upstairs with weapons. Two members of the community helped convince him to leave, Col. Richard Worley said.

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It’s unclear what their relationship was to the shooter. But Worley said the gunman later willingly came out of the building and surrendered.

“We had assistance — great assistance — from the community,” Worley said.

The witness who spoke to The Baltimore Banner has worked at Light Street Animal Hospital for three years. She said vet techs had a dog under anesthesia when she heard Trujillo and his brother arguing.

The two went back and forth for a minute or two, she said, before a co-worker came in and told them to keep it down. She said she heard Trujillo’s brother, Bob, tell her co-worker to mind her own business — and then later heard a loud pop.

The employee, who asked to be identified by her first name, Kayla, because of privacy concerns, said employees called 911 and cared for Trujillo, applying compression to a gunshot wound in his lower leg. Bob Trujillo, whom she described as “unstable” with mental health issues, then threatened another co-worker with the gun before he barricaded himself on the third floor.

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Baltimore City Public Schools called parents at Thomas Johnson Elementary Middle School at about 1:15 p.m. to report that the lockdown was lifted.

This is a developing story. Check back later for more information.