PHOENIX -- A CBS 5 investigation found convicted felons in charge of keeping students safe.

Security guards at Valley high schools interact closely with students, but some have arrest records for crimes like auto theft, assault, shoplifting and lying to police.

One former security guard told 5 Investigates he witnessed guards taking bribes from students, fighting with students and stealing from the school.

He said all of those guards had criminal records.

5 Investigates requested the names of all security guards from six Valley school districts and ran the names through a criminal background check. A dozen had criminal records, with convictions including assault, transporting drugs, disorderly conduct and unlawful discharge of a firearm.

"School districts are just bringing anybody off the street that applies for a job and giving them a job," the former guard said.

Four of the six districts had hired security guards with criminal histories. Paradise Valley has one; Scottsdale has one; Peoria has three; and the Phoenix Union High School district has seven.

Trevor Browne High School employs Michael Nerini, who has an assault conviction.

Maryvale High school employs three ex-convicts as security guards: Vincent Stevenson, convicted of endangering lives with a gun; Theartis McKelvey, convicted of fighting in public; and Moises Longoria, convicted of resisting arrest.

In every case, district officials admitted they knew about the criminal convictions but hired the employees anyway.

The former security guard said administrators have such a hard time filling those positions that they tend to look the other way.

"There's a kind of a, just kind of 'mind your own business' type of attitude," the former guard said.

The school districts are not breaking any laws by hiring those people. While teachers and administrators need to be cleared by the state to work at public schools, security guards do not.

Security guards are fingerprinted and run through background checks, but it's up to the school districts to decide whether a conviction should keep them from working.

"That's not our call on the uncertified. That's up to the hiring board to deal with," said Lt. James Warriner of the Department of Public Safety.

That discretion allowed Saguaro High School in Scottsdale to hire Daniel Auditor, a man convicted of stealing a car and threatening and intimidating, causing bodily injury.

The former security guard who spoke with 5 Investigates said the bottom line is that people with criminal records set the wrong example for students and have proven they don't work well in pressure situations.

"Parent's need to know exactly who's in their schools, who's working in those schools with their kids," the former guard said.

The school districts said hiring decisions are made on an individual basis and that the guards they employ have shown they are qualified for the job.

Interestingly, to be certified as a security guard by the state of Arizona, a person must pass a background check. Schools are not required to hire state-certified security guards.