Who is H in Line of Duty? All the clues, theories and suspects so far

It's the question every Line of Duty fan is asking... WHO. IS. H?

Who is H in Line of Duty? Please tell us!

Line of Duty Season 6 is here and fans couldn’t be more excited.

After the pandemic threw production for the new series into chaos, we have been waiting an agonising two years to get answers to all those questions Series 5 conjured up – with the most important still being, who is H?

We have put all the clues, theories and suspects together in one place – but who do you think is the fourth and final rogue officer? Or are there more?!

Lennie James, Craig Parkinson, Neil Morrissey

Dot (centre) revealed huge clues about the identity of H as his dying declaration (Picture: BBC/World Productions/Ed Miller)

What do we know about H so far? 

H is – or we think is – not one but four corrupt officers. H is a code name referring to a group of senior ranking corrupt police officers within the Central Police.

The revelation that H was not just one individual but actually a group of officers was revealed by DI Matthew Cottan (Craig Parkinson) as his dying declaration in Series 3.

MORE: Craig Parkinson to host Line of Duty podcast

In the Series 3 finale Dot was fatally injured after being shot three times, however, before he passed away he provided essential information about the group of corrupt officers by blinking when Kate Fleming (Vicky McClure) got to the letter H.

However, it wasn’t until Series 5 that Steve Arnott (Martin Compston) noticed that in addition to Dot’s blinking he was also making tapping motions with his hands.

In footage recorded on a police bodycam, Dot could be seen using Morse Code to indicate the letter H wasn’t necessarily the surname of a person, but a wider group.

In Morse Code, H is four dots, leading the AC-12 gang to conclude that there are four senior ranking members in cahoots with organised crime.

Adrian Dunbar as Hastings and Polly Walker as Gill in Line of Duty

Adrian Dunbar as Hastings and Polly Walker as Gill in Line of Duty (Picture: BBC)

Who has been identified as part of the H line up? 

So far the names that have been identified are Cottan himself, Derek Hilton and Senior Legal Counsel Gill Biggeloe, leaving one name that we are still yet to discover.

Who could be the final H?

Superintendent Ted Hastings

Adrian Dunbar as Ted Hastings

Ted might have some secrets, but surely he’s not corrupt? (Picture: BBC)

For a time in series 5, it was believed that our beloved Superintendent Ted Hastings (Adrian Dunbar) could in fact be H.

Not only had he started acting suspiciously, but he had also started to take on some of the traits of H (like the now-famous misspelling of ‘definitely’), leading to him being questioned about the crimes.

Thankfully Ted was eventually relieved of all charges when it was revealed he’d been set up, with his ‘best team’ coming to his rescue as they got their hands on some new evidence.

But have all the loose ends been tied up with Hastings? How much do we really know about what Ted gets up to when he’s not fighting rogue coppers with AC-12?

In season six, Ted has been keeping his head down around AC-12; his reputation has been damaged pretty harshly by his false accusations. Does this remove any suspicions about him? Or is this the perfect opportunity for Ted to go rogue?

DI Kate Fleming

DI Kate Fleming in Line of Duty

Surely Kate couldn’t secretly be H… could she? (Picture: BBC)

In a shock twist, fans have been speculating that the one and only Kate Fleming – one of AC-12’s finest – could in fact be H. They are basing their new theory on two things.

The first is that she looks suspiciously guilty in the new 15 second trailer (above) that has been released by the BBC ahead of the new series starting this month.

The second reason fans think Kate could be secretly corrupt is based on the fact she is so squeaky clean.

While both Steve Arnott and Ted Hastings have both had some slightly dodgy dealings in the past – Steve with his Lindsay Denton drama in series 2 and 3, and Ted with his financial dodgy dealings – but no one has anything on Kate. Yet.

Over the last few series she has been seen getting home late after work, but where has she been? Working hard to bring down dodgy police officers? Or leaking info to the OCG?

So far, we’ve learned that Kate left AC-12 due to her personal differences with Ted’s leadership on Operation Pear Tree in season 5. Maybe that wasn’t the only reason she left. Perhaps she moved departments within the police force to gather better intel for the OCG?

It does seem suspicious that she would turn her back on anti-corruption so easily…

DCI Joanne Davidson 

Kelly Macdonald as Joanne Davidson

Could newcomer Joanne Davidson be the last H? (Picture: BBC)

The new face joining series six is DCI Joanne Davidson, who will be the latest cop to find herself under the scrutiny of AC-12.

Never since it was announced that Trainspotting and Harry Potter actress Kelly Macdonald would be joining the Line of Duty cast it has been suggested by fans that she could be corrupt… could she H hiding in plain sight?

Joanne has been brought in to oversee Operation Lighthouse, an unsolved investigation into the murder of Gail Vella, but while some of her actions certainly arouse suspicion, could she really have an ulterior motive?

Episode 1 of season six dropped some huge hints that point to Jo as a possible H suspect. Is anyone really capable of spotting a robbery in progress in a police convoy travelling at such high speeds? It doesn’t seem likely. 

Then there are Farida’s comments to DS Arnott. Obviously, she’s frightened of Jo and worries for her own safety; why else would she run to AC-12 and dob her boss in?

We desperately want to know what Farida meant when she told Steve he “didn’t know what she’s capable of”? And just what does she need all those locks on her front door for? What’s she hiding?!

DCC Andrea Wise

There are two clues pointing to Detective Chief Constable Andrea Wise, played by Elizabeth Rider, being the last H.

The first clue was her determination to remove AC-12 from the investigation into Operation Pear Tree… perhaps because they were getting too close to uncovering the truth?

The second clue is that she was the one to order a separate inquiry into Ted Hastings… was it her plan to frame him for being H?

DCS Patricia Carmichael

Line of Duty Anna Maxwell Martin

Is Anna Maxwell Martin’s Line of Duty character Patricia Carmichael working with organised crime? (Picture: BBC/World Productions)

Patricia (played by Anna Maxwell Martin) was brought in during Series 5 to investigate Ted Hastings… but her case against him totally fell apart at the last hurdle.

However some fans are convinced that her determination to put the spotlight on Ted was a way of covering her own shady dealings with organised crime.

Patricia is a Detective Chief Superintendent, could she be using her high ranking as a way of running her own team of dodgy cops?

PCC Rohan Sindwhani

We first saw Police and Crime Commissioner Rohan Sindwhani, played by Ace Bhatti, in Series 5, but while it looks unlikely that he has got what it takes to be the next H, he did seem very happy to sweep the disaster that was Operation Pear Tree under the carpet.

He spent a lot of time being advised by Gill, but was she using him to her advantage and he just let her call the shots? Or were they secretly working together?

Or could the final H be someone we haven’t met yet? Only time will tell.

Detective Superintendent Ian Buckells

Buckells has featured in Line of Duty for some time now. As he’s not one of Line of Duty’s main characters, he may not seem the most obvious choice, but he has gotten in the way of AC-12 on multiple occasions.

His biggest mistake is almost certainly giving Kate away as an undercover officer to DCI Roz Huntley in season 4. He wasn’t exactly happy with how AC-12 treats other officers.

Now he’s a Detective Superintendent, he’s climbed quite far up in Central Police Service, so he could well be in a prime position to leak insider info to criminals. His major suspicious move in season six was been delaying giving the go-ahead to Jo Davidson to arrest Ross Tanner, aka Terry Boyle. Perhaps this gave OCG members just enough time to clear evidence out of Terry’s flat…

Series 6 of Line of Duty airs every Sunday from 21st March at 9pm on BBC One.

You can also catch up on series 1-5 on BBC iPlayer

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