The band director says the whole ordeal has been frustrating and a little unbelievable that someone would be so bold as to steal instruments from children, and in one case, the thief walked right through the front door of the building.
A storage closet inside the band hall used to be full of instruments, many of them very expensive.
"On the shelves you had the trumpets, the flutes... the tubas were over there," said band director Brenda Corral-Smith.
Security video shows the thief in action. School administrators say he stole little-by-little, not all at once, over a period of three weeks. Most happened early in the morning before school started.
One incident happened Nov. 3, just before 5 p.m. as students were gearing up for a football game.
"Whoever did it knew exactly what he was getting. He didn't go for the most inexpensive things in the room," Corral-Smith said. "This is a person who knows something about music, that maybe was in a band program in high school. He picked the right instruments. It was only 25, 26 instruments but that was almost $150,000."
Alief ISD leaders say the same man stole an additional $40,000 worth of instruments from Hastings High School, just down the street from Elsik High.
The instruments are all owned by the district.
"Eighty-two percent of our students are on free or reduced lunch, and because of that, we make sure that our kids have every other opportunity that any other high school will have," Elsik High Principal Tina Elzy said.
The district is in the process of replacing the instruments, but it's still a big hit to students who have had a lot of success lately.
"They were at a high and then all of a sudden this happens," Corral-Smith said. "They don't understand that."
The Alief ISD police force is investigating and asking for help finding the man responsible. They hope to find and return the instruments.
Police have added security cameras outside of one of the doors after the thefts and have talked with students about reporting strangers.
If you recognize the man, call police.