Mauricio Mario Ortiz was arrested Friday on accusations that he assaulted a 16-year-old girl at his Redlands gym on Jan. 4.
During the investigation, another woman reported she had been sexually assaulted by Ortiz in Loma Linda in the summer of 2010 when she was 17.
Ortiz was arrested Jan. 6 after investigators served search warrants at his home in the 1500 block of Brookside Avenue and his business, Fitness by Mauricio, at 390 Alabama St., both in Redlands.
During the search at both locations, police said they seized evidence, including cameras, computers and photos.
Redlands police said Ortiz has operated his business at various locations in the area, including Citrus Avenue in downtown Redlands and Mountain View and Barton Road in Loma Linda.
Police said he has been at the Alabama Street location since October 2010.
Mark Taylor, whose business is next door to the fitness facility, watched as detectives collected evidence.
Taylor said that during the search, a customer of Ortiz, who showed up to work out, ended up talking to detectives and said she was unaware her personal trainer had been arrested.
"She was totally surprised that anything was going on," Taylor said. "She said the guy was just as clean as a whistle and has never had any problems, he's a great trainer and has done a great job for her."
Investigators said they believe there may be additional victims and are asking anyone with additional information to contact call Redlands police at (909) 798-7681.
Anonymous tips can be made by texting 274637 using the keyword "REDTIP."