A ROBBER who stole thousands of pounds worth of cash in a string of robberies is behind bars.

Ali Lwanga, aged 21, of Baron Walk, Newham, was found guilty of conspiracy to rob at Wood Green Crown Court in July.

And on Monday, Lwanga, who was caught using state-of-the-art technology, was jailed for eight years.

During Lwanga’s trial evidence was presented on how SmartWater, an invisible liquid which can only be seen under ultra-violet light, played a crucial role in the investigation.

The chemical, installed in the blue security dye in the cashboxes of security firm G4S, meant recovered stolen money could easily be traced back to a number of robberies on security vans.

Lwanga was convicted of conspiring to rob a security van as it made a delivery on January 18, 2008.

He is the first robber to be tried and convicted using Smartwater.

A 16-year-old man was sentenced to three-and-a-half years while three more young men, aged 14, 15 and 16, each received 18 months imprisonment for their parts in the crime.

On January 18, Flying Squad officers were carrying out a surveillance operation on the men.

The group had spent the morning touring north and east London looking for a van to rob before finally settling on a Loomis vehicle at the Cineworld cinema, in Enfield.

Three of the juveniles were in a stolen Renault Megane while Lwanga directed operations from a Vauxhall Astra with the fourth youth.

Two of the youngsters got out of the Megane and tried to wrestle the cash box, containing £3,640, from the security guard.

When he resisted, they wrenched his arm back and forced him to let go.

The youths then made off in the vehicle, but pursuing officers watched the box explode in a cloud of red dye in the back of the Megane as the gang wrenched it open.

The youths were detained while the other youngster was arrested as they regrouped at their base, a fast food restaurant in Barking Road, Newham, a short time later.

Lwanga escaped but was arrested on February 12 after officers tracked him down.

Detectives were first alerted to Lwanga’s activities when he began attempting to launder hundreds of pounds in cash using gaming machines at branches of Ladbrokes in Canning Town in November 2007.

A total of £25,000 was recovered from the Hertford Road heist, while another £50,000 was found from two robberies in Newham.

Investigating officer DC Laurie Bays, from Barking Flying Squad, said: "Lwanga was a prolific robber who claimed he was committing crime to pay off debts. The jury discounted this defence. Lwanga recruited youths to actually carry out the robberies and minimise the risk to himself.

"However, a combination of vigilant Ladbrokes' staff, good detective work and advances in technology mean he didn't get away with it.”