The investigation into longtime Clark County Sheriff’s Office Detective Kevin Harper revolved around an affair he had with a known heroin addict, according to a case summary released Thursday.

Washington State Patrol detectives conducted a criminal investigation and collected evidence that showed Harper witnessed the woman using heroin, did not seize her cellphone during the execution of a search warrant and gave her money when he knew or should have known that it was to help the woman buy heroin, the document states.

Detectives have completed their criminal investigation into Harper and have forwarded the information to the Attorney General’s Office for consideration of charges.

Harper, 57, met Tracy Wasserman in August 2015 when he responded to investigate a death and possible overdose of one of Wasserman’s friends, according to the WSP report.

Over the next few months, the two maintained contact via phone, text and social media, and their relationship grew from professional to friendly and eventually to sexual in nature, the document states.