Knife charges against mentally ill man dropped days before he stabbed academic to death in frenzied attack

'How can it be Femi Nandap was armed with a knife at liberty on the day he killed my husband?' victim's wife asks at inquest

Dr Jeroen Ensink was on his way to post cards announcing the birth of his first child with wife Nadja Ensink-Teich (PA)

Prosecutors dropped charges against a mentally ill man for brandishing a knife in public days before he stabbed a new father to death in a brutal attack, a court has heard.

An inquest into the death of Dr Jeroen Ensink, an academic who worked at the London School of Hygiene and Tropical Medicine, was told that police also failed to file a report that could have led to his killer getting treatment.

Dr Ensink's widow, Nadja Ensink-Teich, demanded answers from the Metropolitan Police and Crown Prosecution Service (CPS) at St Pancras Coroner's Court.

“How can it be Femi Nandap, apparently so mentally unwell, was armed with a knife and was at liberty on the day he killed my husband?” she asked.

The Nigerian student had first been arrested at his sister's house in north-west London after police received reports he had intimidated the public while carrying a knife in May 2015.

PC Adam Wellings told how Nandap snatched his Taser, punched him and tried to bite his nose while grappling with him and another officer.

When questioned by Coroner Mary Hassell, he and PC Stephen McDonagh both said that in “hindsight” they should have created reports on Scotland Yard’s Merlin database, which would have flagged Nandap's vulnerabilities with authorities that could have given him help.

Femi Nandap was sentenced to an indefinite hospital order (PA)

The 25-year-old had already been diagnosed with paranoid schizophrenia, having suffered hallucinations and believing he was a “Messiah” who could communicate telepathically.

While on conditional bail, Nandap returned to Nigeria where he was treated with anti-psychotic drugs and his sister told police chasing up a missed appointment that he was suffering from depression and psychosis.

Nandap was to face trial for possessing a knife and assaulting an officer, but on 23 December 2015 the CPS dropped charges citing “insufficient evidence to provide a realistic prospect of conviction”.

PC Wellings told the court: “I was a bit disappointed and confused as to why he wasn't charged.

"It was not the nicest experience but unfortunately it's not that uncommon with assaults like that for people not to be prosecuted."

A year later, the officer received a letter from a deputy chief crown prosecutor apologising for the ”incorrect“ decision not to pursue the assault charge after a review.

Six days after Nandap was let off the hook, he spotted Dr Ensink as he walked from his home in Islington to post cards announcing the recent birth of his daughter.

Ms Ensink-Teich wept when the court heard how off-duty special constable Maria Hegarty heard cries of "help me, help me" from her home before finding the killer standing over Dr Ensink.

"The male on the floor was not moving, and the male standing up over the man, he was holding a large kitchen knife,” Ms Hegarty said in a statement.

"I tried to encourage him to walk away. He seemed calm.”

A post-mortem examination found the Dutch academic died of shock and haemorrhage, as well as multiple stab wounds to the chest and back from the frenzied attack.

Nandap admitted manslaughter on the grounds of diminished responsibility and was treated at Broadmoor psychiatric hospital.

The Nigerian national, who was in Britain to study at the London School of Economics, has been stripped of leave to remain in the UK and could be deported upon release.

The inquest continues.

Additional reporting by PA