Unforgotten - Season 4

When a headless and handless body is found in a North London scrapyard, the team led by Sunny are called to investigate. They suspect the body was illegally dumped, perhaps transported inside a white goods item. This is confirmed when pathologist Leanne Balcombe finds that the dismembered corpse had been frozen. The body is identified as one Matthew Walsh who went missing 30 years before and we start to meet four people who may be connected with his disappearance.

Cassie and Sunny identify four suspects who trained as police probationers together; two of them are still serving police officers.

Andrews is still unconvinced that there is enough evidence to tie four police officers to the Walsh murder.  But with Fogerty dead, Cassie believes the only way to determine the truth is to interview the passengers of his car on the night in question.

Cassie and Sunny discover Walsh was chased by all four suspects on the night in question. Willets realizes Fiona's blood sample may have been deliberately lost by Liz.

Cassie and Sunny interview two of the suspects again and get closer to the truth of what happened to Walsh. Balcombe believes she may have found the cause of death.

Despite a tragic turn of events, Sunny and the team narrow down the suspects. Will they find conclusive proof of who the murder weapon belonged to?