Levi Bellfield could be one of the most dangerous serial killers Britain has known.

Detectives believe he would have gone on killing, preying on young women, if he had not been stopped.

By day the 39-year-old was a charismatic and charming family man, businessman and Jack the Lad.

However, by night, Bellfield "who hated blondes", regularly prowled for his female victims on streets he knew intimately, leaving them dead or dying after spotting them on buses or near bus stops.

The murders of Marsha McDonnell and Amelie Delagrange, and the attempted murder of Kate Sheedy, between 2001 and 2004, are thought to be only part of his sexual and violent offending against women.

Detectives believe he may have been responsible for 20 other attacks which were never solved. The most serious allegation is the murder of 13-year-old Milly Dowler in 2002, but detectives will also question him about a number of unsolved murders.

These include the killing of Judith Gold in Hampstead, north London, in 1990, and Bellfield's school friend Patsy Morris, 14, who was strangled on Hounslow Heath, west London, in 1980.

In addition to a number of unsolved attacks on people in west London, Bellfield is suspected of date-rape crimes involving young women who were plied with drugs and sexually abused.

Following Bellfield's conviction yesterday, Detective Chief Inspector Colin Sutton, who led the inquiry, said: "When we started dealing with him (Bellfield) he came across as very jokey, like he's your best mate. But he's a cunning individual, violent. He can switch from being nice to being nasty, instantly."

The 6ft tall, 20-stone killer was brought up in west London by his now elderly and ailing mother.

He had ready access to drugs when he worked as a bouncer in pubs and clubs in the Twickenham area. He then hit gold with the demand for wheel-clamping services for businesses with land which could be used for car parks.

He trawled the streets for young runaways from care homes getting off the last bus with nowhere to go. Tempting them with drink and drugs, they soon found themselves in the back of a succession of old cars and vans which were often adapted with darkened windows and carpets.

If he picked the wrong woman and was turned down, he exploded with violence, parking his vehicle and going after them with a hammer or baseball bat.

Bellfield, who had a devil tattoo on his shoulder, denied his Jekyll and Hyde existence right to the end. He tried to convince the jury at the Old Bailey that he was caught up in a miscarriage of justice.

But a succession of friends and former colleagues told police a different story, of a man who had an unhealthy interest in sex.

Bellfield had a series of blonde lovers. Sometimes, more than one was pregnant at the same time. When he was violent towards a partner, she would seek comfort from one of the other women. They lived in the same area and knew each other. One said Bellfield showed an unhealthy interest in one of her 13-year-old relatives.

He was said to have 11 children aged from three to 18 with five women, but an unofficial estimate put the number of offspring at 13.

Over the years, he had many girlfriends in addition to his "wives" but still sought younger and younger girls to impress.

A former partner said she found a magazine with the faces of blonde models slashed out. Bellfield told her he would go to alleyways and would wait and watch blondes passing, claiming that he wanted to "hurt them, stab them, rape them".

Prosecutor Brian Altman told the court: "He hated women. He hated blonde women."

One of his former lovers, Emma Mills, who lived with him for eight years, told the court their relationship had often been stormy.

She said it was during one of many bust-ups that she moved away to a rented flat in Walton-on-Thames in Surrey.

A short time later Bellfield begged her to return and moved in with her at the flat near the station where schoolgirl Milly Dowler disappeared in March 2002.

Victims of a Jekyll and Hyde character KATE Sheedy SHE was aged 18 and had been out in Twickenham with friends celebrating her last day at Gumley House Convent School, where she was head girl, when she was mown down by a car.

As she lay in immense pain after the incident she begged a policeman: "Please get the b******s."

Ms Sheedy told her parents she thought she was going to die after the incident. As she lay horrifically injured in the road, she told them: "I love you daddy, I love you mummy."

Ms Sheedy, now 21, fought back to health to face the man who tried to kill her across an Old Bailey courtroom.

MARSHA McDonnell THE 19-year-old had completed her A levels and was taking a gap year before starting university when she died in February 2003.

It was while the teenager was waiting for a bus after going to the cinema with her friends that she caught the eye of Levi Bellfield who was cruising around in his car.

As she walked to the family home a few yards away after leaving the bus she was approached by Bellfield and hit on the head with a hammer.

A neighbour heard a short scream as she lay dying in a pool of blood just after midnight. She was discovered a short time later by neighbours who raised the alarm.

Ms McDonnell died the following afternoon from severe brain injuries with her parents at her hospital bedside.

AMELIE Delagrange THE French student, 22, had moved to Britain to study and had been living in Twickenham for just three months when she was killed.

Ms Delagrange was working at a patisserie in Richmond, had a close circle of both English and French friends, and was happy, the Old Bailey heard.

She met a violent end on a cricket pitch in August 2004 after refusing Bellfield's advances. He struck her down with a hammer as she crossed Twickenham Green in West London at about 10pm after she got off at the wrong bus stop.

Bellfield had been cruising around in a van trying to pick up women who took his fancy.