WICHITA, Kan. (KSNW) -- The sheriff says a Sedgwick County detective who investigated crimes against children is now the focus of a criminal investigation. Sheriff Jeff Easter asked the Wichita Police Department to investigate the detective who had been assigned to the Internet Crimes Against Children section within the Exploited and Missing Children's Unit. Easter said a review revealed "improper case closures and a failure to thoroughly investigate criminal complaints from 2019 to 2024." In December, the Sedgwick County Sheriff's Office began an administrative review of the detective's cases. Man convicted of Wichita murder dies in prison "Upon determining that criminal conduct may have occurred, SGSO notified WPD and activated the Wichita and Sedgwick County Advanced Law Enforcement Response Team (ALERT) to conduct a criminal investigation," the sheriff's office said in a news release. The detective, who was assigned to EMCU in 2019 and transferred to ICAC in 2021, is on paid administrative leave pending the outcome of the investigation. Once the investigation is complete, the appropriate charging authority will determine whether charges are filed against the detective. In the meantime, EMCU investigators will re-contact individuals involved in the cases. The sheriff's office says the investigators are specially trained to handle trauma cases and to ensure each case undergoes a thorough review. After the review, each case will be presented to the Sedgwick County District Attorney’s Office for formal charging consideration. The sheriff declined KSN's request for an interview. "Given the sensitive and ongoing nature of this investigation, no additional details will be provided at this time to protect the integrity of the process and the privacy of survivors," the sheriff's office said. EMCU is a collaborative effort between the Sedgwick County Sheriff's Office, the Wichita Police Department, and the Kansas Department for Children and Families. It investigates serious crimes against children. "For nearly four decades, this unique partnership has been a cornerstone of child protection efforts in Kansas and beyond," the sheriff's office said. "The SGSO and its partner agencies remain committed to maintaining the highest standards of investigative practices and survivor care in all cases." District Attorney Marc Bennett provided KSN the following statement: "The Sheriff’s Office notified the Office of the District Attorney immediately, when the information came to light.  Since that time, this office assisted first, the Sheriff’s Office and more recently, the Wichita Police Department with the gathering of information necessary to conduct an exhaustive  investigation.  When that investigation is complete, a full review of the matter will be conducted by the Office of The District Attorney in order to ensure appropriate disclosures are made and potential criminal charges are considered and addressed."