McKinney police have released the results of its internal investigation into the department's handling of sexual assault allegations against a chiropractor.
Dr. David Russell is accused of sexually assaulting two teenage girls while treating them for groin injuries at his clinic.
The McKinney Police Department admitted it made mistakes in its handling of information in the case. Three officers were disciplined in the matter.
Russell's attorney, Todd Shapiro, said the results of the investigation calls into question the integrity of the department's case against his client.
"Usually, you have to press really hard to get a police officer to admit a mistake," he said. "Here we are, pre-grand jury, and the police have issued a six-page memo that's made public that they made mistakes in this case. It's very unusual.”
A formal criminal investigation into Russell did not begin until Oct. 12. However, the department's internal inquiry shows that a third-party witness called police with detailed information accusing Russell on Feb. 15.
That interaction with a communications specialist did not follow procedure, according to the internal investigation. The call was not documented, nor did the specialist forward the information to detectives.
Later that day, the witness also came to police headquarters and spoke with an on-duty lobby officer, relaying the allegations against Russell. Police said that because the witness wanted to remain anonymous, no statement was made and the witness was given contact information for the Special Victims Unit supervisor.
The witness contacted police again the next day, Feb. 15, and asked to speak with the SVU supervisor.
On two occasions, the witness was transferred to what communications believed was the correct extension but the phone database was out-of-date, police said.
"The phone message came in. It didn't reach the right person," Deputy Chief Scott Brewer said.
Brewer described the situation as a "set of circumstances that compounded one another."
In July, the Special Victims Unit received an information and referral report from Child Protective Services about allegations of sexual misconduct by Russell. According to the department's internal investigation, the email was "mishandled" and did not prompt further investigation.
Police launched a criminal investigation into Russell on Oct. 12 after a report was filed and information was passed along to the detectives.
“I believe the jury that hears David Russell's case will have to be made aware of the mistakes that were made and will have to consider whether those mistakes compromised this case," Shapiro said.
In the time between the witness' first phone call in February and Oct. 12, an additional victim reported alleged sexual assault.
"What is important to note is that we should have and could have done our duty to investigate these matters," Brewer said.
Brewer said McKinney police take all crimes very seriously and have since reorganized to provide "greater supervision at all levels," according to a report on the department's internal investigation.
Each of the three disciplined officers will receive a formal letter of reprimand in his or her permanent personnel file.
The communications specialist mentioned in the report is no longer with the department.
NBC 5's Ellen Goldberg contributed to this report.