A fight broke out between a bookkeeper and a technician while the two were watching a roller derby match, and the technician died as a result of his injuries. The bookeeper was charged with murder. At his criminal trial, the bookeeper called a witness to testify that he had seen the fight and that from what he had observed, the technician had been the aggressor. The witness also testified that he had worked with the bookkeeper and the technician for several years and, in his opinion, the bookkeeper was a peaceful man, but the technician had a reputation for violence. The prosecution then called the technician's son to the stand, who proposed to testify that his father was a peaceful, non-violent person. The defense objected.

Is the son's testimony admissible?