"Yorkshire Ripper" thought to have committed more crimes

LONDON, June 2 (Reuters) The ''Yorkshire Ripper'' probably committed more attacks than were officially attributed to him, according to a secret report that refers to a ''curious and unexplained lull'' in Peter Sutcliffe's criminal activity.

A 1981 report by Inspector of Constabulary Lawrence Byford refers to the period between 1969 -- when Sutcliffe first came to the attention of police -- and 1975, the year of the first recognised Yorkshire Ripper attack.

''Between 1969 and the start of the known Ripper crimes in 1975 there is a curious and unexplanied lull in Sutcliffe's criminal activities and there is the possibility that he carried out other attacks on prostitutes and unaccompanied women during that period,'' wrote Byford, who was commissioned to review the police investigation of the case.

The report was released by the Home Office under the Freedom of Information Act.

Whether Sutcliffe's murderous reign began before 1975, there is no doubt his killings of prostitutes and unaccompanied women in the Yorkshire and Greater Manchester area prompted widespread fear among the female population until his arrest in January 1981.

After one of Britain's biggest manhunts he was finally caught by a rookie constable who found him with a prostitute in a car bearing false registration plates.

He was sentenced to life for the murders of 13 women and the attempted murder of seven others.

The first of the crimes for which Sutcliffe was convicted was the attempted murder of Anna Rogulskyi in Keighley in July 1975.

Sutcliffe attacked her with a hammer and left her for dead and the attack was not linked to the Ripper murders until 1978.

However, as far back as 1969 Sutcliffe, described in the Byford report as an ''otherwise unremarkable young man'', came to the notice of police on two occasions in connection with incidents involving prostitutes.

The report said that although Sutcliffe's police files on the two incidents had been routinely weeded out by the time the report was written in December 1981, it was clear he had on one occasion attacked a Bradford prostitute with a cosh.

Later in 1969 he was also arrested in the red light district of the city in possession of a hammer.

Instead of thinking Sutcliffe might use the hammer as an offensive weapon, officers thought he was a burglar and he was charged with ''going equipped for stealing.'' Byford said a number of assaults since 1969 in some way fall into the ''established pattern of Sutcliffe's overall modus operandi''.

''It is highly improbable that the crimes in respect of which Sutcliffe has been charged and convicted are the only ones attributable to him.'' REUTERS SI PM0929