Arlene accused had killed before

Robert Howard, seen at a previous court hearing, is a convicted killer

A man acquitted of murdering Northern Ireland schoolgirl Arlene Arkinson is a convicted killer, child abuser and rapist, it has been revealed.

Robert Lesarian Howard's 40-year record was subject to a publicity ban for the past two years while he was before the courts in Northern Ireland.

However, reporting restrictions were lifted on Tuesday as other serious sex offences against him were dropped.

Howard, 61, is serving life for the rape and murder of a London schoolgirl.

In June, a jury acquitted Howard - by a majority verdict of 10 to two - of killing 15-year-old Arlene Arkinson in 1994.

Arlene vanished near her home in Castlederg after attending a disco at Bundoran in County Donegal with friends in August 1994. Howard, formerly lived in Main Street in Castlederg.

Extensive searches were carried out but no firm evidence of the teenager still being alive was ever found and her body has not been discovered.

As reporting restrictions were lifted at Belfast Crown Court, it emerged that Howard's criminal record dated back 40 years.

Arlene's sister, Kathleen, said the jury was unaware of Howard's criminal history and she did not blame any juror for the acquittal verdict.

"They knew nothing about him, nothing at all. And we were sitting there and we knew his past from we were in Kent," she said.

"We were like: 'My God, why can't they not let you know he is already doing life? Look at his convictions.' We were sitting frustrated. We felt like just roaring it out, but we couldn't."

Life sentence

Howard was convicted of murdering 15-year-old schoolgirl Hannah Williams and sentenced to life in October 2003. Her body was found in Kent.

The English court, which sentenced Howard, was allowed to hear a cross-over of evidence, unlike in Northern Ireland, to prove a "system" of how he groomed his victim through her mother or a friend, after attaching himself to the family.

Arlene Arkinson went missing after attending a disco in County Donegal

Hannah was reported missing from Deptford in south London on 21 April 2001.

Her body, a rope tied around her head, was uncovered by workmen on the Channel Tunnel near Northfleet in Kent almost a year later.

Police in England and Ireland suspect Howard may be linked to the disappearance of up to six women.

It is understood that Irish police have reopened two missing person cases.

They are that of 21-year-old Jo Jo Dullard who vanished while hitching a lift to her home in County Kildare and that of Annie McCarrick, 26, who lived in Dublin. She went missing in 1993 while walking in County Wicklow.

Howard's record showed he was convicted of burglary when he was 13.

His sex crimes began when he was aged 19 in 1965, when he entered a six-year-old's bedroom pretending to be a doctor and was convicted of attempted unlawful carnal knowledge.

Four years later he was jailed for six years for the attempted rape of a woman after he broke into her Durham home.

In 1973, he raped a 58-year-old woman twice in her home after robbing her.

Howard then moved to the County Tyrone area, where in 1995 he was convicted of the unlawful carnal knowledge of a 16-year-old girl in the early 1990s.