(CNN) A Texas police department is apologizing for its treatment of an African-American man that the police chief said caused the man "unnecessary embarrassment."

Photos show two mounted officers from the Galveston Police Department escorting a handcuffed man. One officer is leading the man, identified as 43-year-old Donald Neely, with what appears to be a rope. Neely was arrested and charged with criminal trespass Saturday, according to police. He was released Sunday, police said.

Police said the officer is holding a "line" that was clipped to the man's handcuffs, not a rope.

"While this technique of using mounted horses to transport a person during an arrest is considered a best practice in certain scenarios, such as during crowd control, the practice was not used correctly in this instance," police said in a statement. There was no transportation immediately available at the time of the arrest, police said.

The officers showed "poor judgment" and "could have waited for a transport unit at the location of the arrest," Galveston Police Chief Vernon L. Hale III said.

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