Acting on a tip-off by a former member of staff, I went under cover for BBC Inside Out East Midlands.
What I found shocked me. On my very first night in September 2006 it was apparent things were not working and public safety was potentially at risk.
Within an hour of starting another member of staff highlighted the "missing status" problem.
He said the offender hadn't been monitored for weeks and told me this was because of faulty kit.
That was the start of my undercover experience at G4S in Nottingham.
For four months and 12 days I kept my eyes open, recording the nightly blunders, non-monitoring and general chaos from inside the office responsible for monitoring 1,000 offenders in the East Midlands.
But just witnessing it was not going to be good enough if we were to be able to broadcast our findings.
And G4S is a global player with a large bank balance who would be able to mount a strong legal challenge. For this reason I had to make sure my notes were accurate and detailed.
I also had to ensure my camera would be good enough - I experimented with different types of cameras until finally the team helped me find the right one. It was completely undetectable.
So what was it like to pretend to be someone else? To be honest the person I pretended to be was very close to the real me.
The only thing I had to get used to was my new name. I could not use my actual name as an internet search would have revealed I was a journalist with four years of undercover experience.
During my time at G4S I found staff who were inadequately equipped and severely demoralised - kit that simply wasn't up to the job and a culture of cover-up.
If they weren't doing such an important job it would have been funny.
In fact it was farcical but the bottom line was offenders, including paedophiles, a suspected terrorist on a control order and a man described as a murderer, were not being monitored.
Some of the staff didn't seem to care. Those that did felt helpless in the face of inadequate kit and a lack of resources.
Others complained to their managers but felt ignored. It was a running joke that the kit used to monitor offenders was simply not up to the job.
Some faulty monitoring boxes came back every night, accompanied by the usual comments from staff about how utterly useless it was. If I thought about it, it made me angry. Very angry.
Why wasn't anyone in government aware of this? Why hadn't the Home Office picked it up in the audits in which they regularly crow about?
The audits obviously weren't worth the paper they were printed on because what I witnessed was nothing short of an absolute mess.
Here is a security company that prides itself on being number one in the UK. It boasts about how much of a global player it is in all areas of security. Yet here I am an undercover journalist, with a fictitious name inside their East Midlands operation.
I would watch nightly episodes akin to the TV series the Office. But instead of harmless tittle tattle, I was witnessing serious failings which potentially put the public safety at risk.
It was hard to remain silent. But too much complaining raised suspicious eyebrows.
Staff worked under a blanket of silence. No one did anything about the problems. If you raised concerns you stuck out. You were not one of them.
The agreed policy was to pass the buck. "Not my problem mate, that's someone else's job." You were just supposed to follow orders. Well I wasn't for following orders.