DENVER -- One Denver Department of Human Services employee supervised three recent high-profile child-abuse investigations, a CALL7 Investigation has found.

DDHS supervisor Mary Peagler signed off on closing assessments on the cases of Chandler Grafner, Neveah Gallegos and Luz Valdez in the days or months before the children died, according to DDHS records and interviews.

The day after CALL7 Investigator John Ferrugia reported that human services workers did not interview the alleged perpetrator in the Luz Valdez case, Peagler was put on a month-long, paid investigative leave, DDHS records show.

She returned Feb. 5 and was placed on a performance improvement plan that required her to review the quality of assessments, use a new check list and regularly discuss assessments with staff, records show. She is one of eight supervisors in the unit.

Shari Shink, executive director of the Rocky Mountain Children’s Law Center, said having one supervisor with three fatalities in less than a year may be a sign of a systematic problem.

"When you have the same supervisor involved in three different deaths in a year, is that a red flag?” Ferrugia asked.

"Yes, that's a red flag," Shink said.

“And why?" Ferrugia asked.

"Any time there's any kind of a pattern of anything we need to look at it,” Shink responded. “It basically cries out for some attention.”

"It's a judgment issue?" Ferrugia asked

"Absolutely. Absolutely," Shink answered.

Peagler declined to talk to 7News.

DDHS manager Roxane White also said she could not discuss the situation but conceded interviewing an alleged perpetrator is key in investigating abuse.

“If the person is accused of abuse, then that person should be interviewed?” Ferrugia asked White.

“Absolutely, he should be interviewed,” she answered.

“The alleged perpetrator wasn’t interviewed. Is that a mistake?” Ferrugia asked.

“Yes, that’s a mistake,” White said.

Luz Valdez died in December and her mother’s boyfriend was charged with murder. The boyfriend, Isidoro Valdez-Ruelas, 24, had been investigated on suspicion of dropping the 3-month-old, but human services closed the case without interviewing Valdez-Ruelas, according to the family.

“Did the case worker ask Isidoro about that?” Ferrugia asked Luz’s mother.

“No,” she answered.

“She didn’t question him about it?” Ferrugia asked.

“She didn’t question him about it,” she answered.

Peagler also signed off on closing 7-year-old Chandler’s assessment. He died in May and his caregivers have been charged with murder. DDHS did not follow up on a report that Chandler was taken out of school the month before his death.

Neveah Gallegos, 3, died in September and her mother’s boyfriend, a registered sex offender, is the main suspect in the case, police said. Records show DDHS investigated allegations that the boyfriend, a year before Neveah's death, sexually abused the girl. He has not been charged in either case.

Sources say Peagler was also the supervisor in the Gallegos case.

Supervisors will review Peagler’s performance every two weeks for at least three months, records show. Her former supervisor Margaret Booker, who oversaw Peagler's work during the Grafner case, also was put on a performance improvement plan earlier this year, according to documents.

Despite the recent issues, Peagler previous performance reviews showed that she exceed expectations in her past seven years as a DDHS supervisor.

Previous 7News investigations of the Grafner and Gallegos prompted an internal review of policies and procedures at the Denver Department of Human Services. The review is scheduled to be completed at the end of the month.