Alisha Carrasco Knighten, a P.E. coach at Bonham Junior High and assistant softball coach at Permian High School, resigned Wednesday amid an investigation of a possible improper relationship with a student, Director of Communications Mike Adkins said by email on Friday.

An investigation by Ector County Independent School District police was initiated this week to look into potential criminal charges.

Carrasco Knighten was placed on paid administrative leave on Monday. Her resignation was effective immediately on Wednesday, Adkins said.

Carrasco Knighten, 25, was hired by ECISD as a P.E. teacher at Bonham in May 2013. She is the fourth female employee from Permian in about a year to resign while being investigated of an alleged improper relationship between an employee and a student.

In April 2013, Kathryn Maples and April Collins resigned and were eventually indicted in the second-degree felony. Another Permian employee resigned in April 2014 amid allegations by parents and students to ECISD police of a relationship.

Superintendent Thomas Crowe has said that any relationships are “totally inappropriate” and that the occurrence of such relationships “continues to amaze (him) that educators would put themselves in that position.”

Kathryn Maples, then 28, was a history teacher and swim coach at Permian and supposedly involved with a 17-year-old student.

April Collins, also 28 at the time of the investigation, was employed at Permian as an athletic trainer and was supposedly involved with a 19-year-old student.

Following ECISD’s investigation, no charges were filed. Not until Ector County’s District Attorney Bobby Bland went to the ECISD police department in May 2013 seeking information was when Collins and Maples faced criminal prosecution.

An Ector County grand jury indicted both women on charges of an improper relationship between an educator and student (Maples on three counts; Collins on four counts including sending sexually explicit pictures and online solicitation of a student), a second-degree felony and could carry between two and 20 years in prison and a fine up to $10,000.

Maples was arrested on June 12 and Collins was arrested on June 17.

No trial date has been set for either case, according to documents in the 244th District Court where the women were previously arraigned.

On March 20, former Permian math teacher Robert Young, 44, was acquitted on two counts of improper relationship between educator and student.

He was placed on administrative leave June 21, 2010, during the investigation of a relationship with an 18-year-old female student. Young was arrested June 29, 2010.