Scotland Yard: Insufficient evidence to arrest Alice Gross suspect

LONDON, Sept. 25 (UPI) -- Authorities in London say they don't have enough evidence to arrest the convicted murderer who has been named the prime suspect in the disappearance of teenager Alice Gross.

Scotland Yard said Arnis Zalkalns, if found in his native Latvia, would remain free because the evidence they have against him falls short of the threshold required to obtain a European arrest warrant.

Graham McNulty, commander of the Metropolitan Police, said they could not seek a European arrest warrant until they were ready to charge a suspect.

Alice, 14, disappeared in west London nearly a month ago. She can be seen on CCTV on August 28th walking by a west London canal. Zalkalns can be seen riding a bicycle in the same area 15 minutes later: Detectives say they believe the two would have crossed paths.

The Met named Zalkalns as a prime suspect in her disappearance: He was last seen on September 3rd, a week after Alice went missing.

"There is no evidence that Alice has come to harm, but we are clearly very concerned for her welfare," McNulty said. "I would urge everyone to be cautious about speculating on the exact involvement of Arnis Zalkalns, or any other individual, in relation to this investigation."

It's not clear where Zalkalns is: McNulty says if he were located inside the U.K., he could be arrested on suspicion. And Latvian police spokesman Toms Sadovskis said there is no evidence Zalkalns had entered or tried to enter the country.

Zalkalns was convicted of the murder of his wife in Latvia and began serving an eight-year prison sentence in 1998. He was also arrested in 2009 for the alleged indecent assault of a teen girl in Ealing, west London. The case was dropped when the girl declined to make a statement.