A disgruntled customer who threw a petrol bomb into a crowded clothing store, engulfing a six-year-old girl in a ball of flames, was yesterday jailed for life.

Asa Lawrence, 25, was found guilty of causing grievous bodily harm with intent following a four-day trial at Birmingham Crown Court earlier this year.

Sentencing Lawrence at the same court today, Judge David Matthews ordered that the double glazing salesman should not be considered for parole for at least seven years.

The judge said the defendant, of Merridale Road, Wolverhampton, was a "dangerous young man" and that the offence - committed last summer at the TK Maxx store in Perry Barr, Birmingham - had been an evil act.

The judge said Lawrence, who refused to leave the cells to hear his fate, would remain on licence for life after his eventual release.

Lawrence had launched the attack as an act of revenge "out of all proportion to any perceived grievance" following a petty dispute with management 24 hours earlier.

The offence was committed on the afternoon of August 27 last year as Shae Thomas, her mother Cherra Johnson, and grandmother Nora Johnson were entering the shop.

Shae, from Bristol, suffered serious burns to her head, shoulder and arm after the firebomb clipped the underside of an internal door frame, exploding in mid-air and showering her with burning petrol vapours.

Judge Matthews said: "It was to have the most terrible consequences for a pretty and vibrant little girl, who was just six years old at the time.

"While Asa Lawrence is an intelligent and articulate young man, he is also violent, capable of irrational anger and resentment, and capable when angry of causing serious harm.

"In my judgment he is a dangerous young man from whom the public requires protection for an indefinite period until others deem it appropriate for him to return to the community."

The judge accepted a psychiatric report which found Lawrence to be suffering from a paranoid personality disorder.

The defendant claimed at his trial that he had aimed the missile at a display rack and had not intended to hurt anyone.

Speaking outside court, Cherra Johnson said: "I am quite pleased. He's a really big threat and he's inside now.

"I can now get on with my life."

Ms Johnson, who was also injured by the incident, revealed that her daughter - who is still facing further skin graft operations - was attending a school sports day today.

The court heard that Lawrence had a "significant" criminal record and had assaulted a member of staff at an Asda store in Wolverhampton with a baseball bat in April last year after a trivial disagreement.

Lawrence was cleared of attempted of murder at his trial, but was found guilty by a jury of causing grievous bodily harm with intent.

He had admitted causing an explosion likely to endanger life and causing bodily injury by explosion to Shae and her mother.

He was given four life sentences to run concurrently for what the judge described as the "extraordinary circumstances" surrounding the attack.

"None of us who saw the pictures of the damage that it (the bomb) caused to the little girl's face and limbs is ever likely to forget them," Judge Matthews said.