WREG looks into school security after unwanted visitors enter side door

MEMPHIS, Tenn.-- Keeping danger out is a constant struggle for schools. which is why WREG is digging deeper. 
We began our investigation in March, after a fight at Ridgeway High School after two women barged into the school and beat a girl.  Students told us they came in through an unlocked side door.
We've had crews come check to see what the deal is with the side doors at least three times.
We were at the school Friday and also earlier this week and did see a door with students able to come and go.
Parents we talked to were uneasy about the access and wondering why it isn't locked.
"The front door is like that, all the other doors should be like that," said one mother. 
Another father added, "My daughter is here so that's very concerning."
However, it's not completely clear if someone is on the inside letting the students in.
In some cases it appears an employee was opening the door. 
On one visit a door was propped open while it looked like construction was going on nearby.
Ridgeway isn't the only school that has seen unwelcome visitors. In March a man was able to force his way past an employee taking out the trash at Alcy Elementary...and stab his wife with a screwdriver in the cafeteria. 
Ken Trump, President of National School Safety and Security Services is a school safety expert
He says schools often invest heavily into physical security measures like cameras and metal detectors but there are other simple things to do.
 "Not only closing a door and making sure it's locked but also making sure that if somebody gets past that door, someone props it open and people get in, if someone legitimately gets buzzed into an entrance way and two or three people follow behind them, the staff on the other side of that fortified entrance know what to do and are aware of strangers in the building," said Trump.
He says it often boils down to employees and being prepared. 
"The best line of defense is always a well-trained staff and student body. Simple things such as access control, making sure doors are closed, making sure you have visitor management systems are all tools so it comes down to the people side of school safety as much as the hardware side."
Shelby County Schools told us exterior doors are to remain closed and locked at all times including the cafeteria and gym doors.