Denise Keesee, 39, pleaded guilty Monday to sexually abusing a 16-year-old boy who was a student at Sherwood High School, where she was a teacher.

Facing six counts of second-degree sexual abuse involving two students, Keesee took a plea deal and admitted to two of the counts involving one victim.

Keesee's relationship with the victim was first investigated in 2008, when the boy's mother reported finding inappropriate text messages between the teacher and her son. But the investigation was dropped until allegations involving another student surfaced in 2012.

The Washington County Sheriff's Office handled the investigation because Keesee is married to a Sherwood police officer, who was the school resource officer from 2011 to late 2012.

Deputy District Attorney Paul Maloney said Monday that Keesee told detectives she did have sex withthe student in 2008. According to court records, Keesee said they had sex several times at various locations, including her home, the boy's home and a Tualatin park. The student was 16 at the time, records say.

Detective Robert Rookhuyzen said last year the relationship was long-term, and that the victim became convinced that Keesee would marry him after he graduated.

Keesee contacted Sherwood police in May 2008, according to court records, because she was worried about the student's mental health. She had received an email from the boy that contained a poem expressing regrets and suicidal thoughts, including the lines:

"im sick of life and how im lying

im sick of this earth and what im trying to do

im sick of everything just want to be true"

Rookhuyzen said it wasn't clear