Trust, and don’t verify.

City education officials maintain they did a “robust” background check on the psycho ex-cop who was working with Brooklyn elementary-school kids before and after he allegedly killed a jogger  —  making the assertion despite a string of deeply disturbing red flags showing otherwise.

The Department of Education  told The Post that its applicants such as accused killer paraprofessional Sayed Mohassib, 27, are subject to “a robust background and review process for employment,” including “a fingerprint-supported background investigation to determine whether security clearance can be granted for the position thought.”

DOE job-seekers  also  “must complete a detailed background questionnaire that includes questions about several topics, including but not limited to previous adverse employment, adverse military service and past criminal history.

“Candidates must also certify that [the] answers they provide are truthful,‘’ the DOE said — failing to say whether the department actually checks that applicants are  being honest and how they vet answers.

Prior to his stint at PS 200,  the accused killer lasted at the NYPD just six weeks in 2022 before he enlisted in the Marines — who swiftly booted him after a month because of psych issues.

The NYPD then refused to take him back when he reapplied to the force — even calling an ambulance to cart him off to  Bellevue Hospital for a mental-health evaluation because of unhinged behavior, sources said.

Cops were then called to Mohassib’s family home when he threatened to “chop up’’ his family in 2024 — the same year that city Department of Education records show he was working for the agency.

Mohassib continued working for PS 200 up until the random murder of jogger Katie Suarez on Oct. 30 — and even after, till cops were able to nab him Saturday.

Either Mohassib’s DOE questionnaire falsely did not include his time with the Marines and NYPD — and was never caught by the agency — or  he noted his armed service and stint with the Police Department and either the DOE never bothered to do its due diligence and inquire about both, or ignored its findings.

“How this guy got through a background is startling,” said former DOE Deputy Chancellor Eric Nadelstern, who served in the Bloomberg administration, to The Post.

“Did they cut corners?

“Any background check should be looking for: Is the person a convicted violent felon, a child molester?. We should be looking for whether someone is not in control of his behavior. You’re looking for if someone has a history of alcohol or drug abuse.”

Troubled PS 200 dad Tan ver Awan said Tuesday, “I don’t understand, who hired him?

“So what does DOE do? No checks? No good. This is a job where they have to be even more careful.”

A mom who asked to remain anonymous said school higher-ups held a meeting with  parents this morning and that a previous hallway incident involving Mohassib was mentioned but that no answers were given to questions about it — or the suspect’s hiring.

“Their answer was, it wasn’t them — they didn’t hire him,‘’ she said of school officials.

“I left disgusted. Now I’m angry.‘’

Here’s the latest on Katie Suarez, the NYC jogger who was stabbed during a run:

City Councilman Frank Morano vowed to introduce legislation to shore up the hiring process for city school staffers.

“I don’t know what the DOE knew or didn’t know, and that’s part of what I’d like to find out,” he told The Post on Tuesday.

“I’m not claiming the DOE broke any rules,” the pol said. “I’m asking whether the rules that we have are good enough. Maybe the DOE followed all the rules, and if that’s the case, we need to change. It think it’s just common sense.”

While sources said Mohassib openly acknowledged to coworkers that he suffered from mental-health issues and took meds, his employer the DOE said federal law prohibits it from accessing workers’ related records.

In the weeks leading up to Suarez’s death on a path at a popular Bath Beach park, Mohassib also was the subject of at least 10 coworker complaints to school higher-ups over bizarre behavior, troubling tattoos and a gun pendant he wore to school.

Administrators shut down those concerns, telling the school workers they were being racist and to just stay off social media if they didn’t like the photos that Mohassib was posting, sources told The Post.

According to sources, the failed cop’s aunt works as an assistant principal at another city school and his sister is also a paraprofessional at PS 200, which he once attended as a student.

Mohassib was initially hired as a part-timer but was given a full-time job as a paraprofessional in March, sources said.

Coworkers at PS 200 grew concerned over his bizarre behavior, including a “blank stare,” a gun pendant he wore to school, and a series of chilling Instagram photos that reveal disturbing full-torso tattoos that include the word “Allah” and “Death,” the names of historic Muslim figures, and large drawings of a shark and a tiger.

Officials at the United Federation of Teachers did not respond to a Post request for comment, nor did PS 200’s principal and assistant principal.

Mohassib was indicted on second-degree-murder charges and is being held at Rikers Island.

This is a developing story. Please check back for updates.