A sexual assault investigation lead to the discovery of a make-shift dentist office inside a mobile home in Brownsville.
Brownsville police confiscated patient information and illegal meds.
Police said Sergio Jefferson was practicing dentistry without a license on hundreds of patients, but this may not have been his only illegal medical practice.
His arrest comes after a teen was allegedly sexually assaulted during a pregnancy check-up.
"There was always people coming in and out, and I remember getting knocks at my door asking for a doctor. "
This man, who we TMll call angel, said he was shocked to see his neighbor's home surrounded by police and Federal Immigration Customs Enforcement agents recently.
Authorities arrested 56-year-old Sergio Jefferson at his home, on charges of sexual assault of a child.
According to police, a 14-year-old girl was looking for doctor when she suspected she was pregnant and was referred to Jefferson.
"So this female went to see the doctor and he sexually assaulted her, said Billy Killebrew with the Brownsville Police Department. She was on a bed with her clothes off and he digitally penetrated her.
That investigation led to another discovery.
Inside Jefferson's home, police found a make shift dentist office with log books detailing patient information and appointments and several boxes of numbing medication.
Angel said he didn TMt interact much with his neighbor, but adds there was something obviously going on at the home and for years.
"I want to say about a good six or seven years, said Angel. So there was a lot of commotion usually throughout the week, so I just put two and two together. Like I said people would knock on my door asking for a dentist, and I would see them eventually going next door"
Angel said he suspects his neighbor may have been a licensed Mexican doctor that set up shop on this side of the border, but authorities said that's illegal.
"You have to be board certified on this side on the U.S. side. There's different rules and regulations that apply between two countries " said Killebrew.
Police ask anyone who may have been a victim of malpractice or any other crime while seeing Jefferson to report the crime.