Police say a 30-year-old Utah State Prison parolee has admitted that he committed a string of art robberies and is helping investigators with efforts to recover the missing work.

Police believe the man is responsible for four robberies of three galleries, dating back to November 2007.

Davis County sheriff's detective Ken Warnshuis said they are not ready to release the name of the man, who has not been formally charged, but noted that he is being held on parole violations unrelated to the robberies.

Warnshuis said an interagency investigation that included law enforcement officers from Davis County, Salt Lake City and Saratoga Springs led to the man, who is a former art gallery employee and "very savvy about art."

"As a person who had worked for a gallery, this guy knew how things worked," Warnshuis said. "He knew what to take and what to leave ... he passed on the lesser-quality work."

Warnshuis said police had recovered four of nine pieces that were stolen in two separate robberies, one last November and another in April, of the Canyon Gallery in Fruit Heights. Seven of the nine were works by James Christensen, a popular and highly collectible Utah artist. Other galleries targeted by the man include the Repartee Gallery in Salt Lake City and a gallery in Saratoga Springs.

Two additional pieces were recovered Thursday afternoon, and Warnshuis said he hoped more of the work will be found.

Warnshuis said tips from former gallery employees, tire and shoe track evidence gathered at the second Canyon Gallery robbery in April, and the sharp eye of a Sandy city police officer — who remembered artwork in the trunk of a man pulled over for a traffic violation — all contributed to tracking down the man.

Warnshuis said charges could be filed at any time but are hoping to recover more of the missing artwork before making the man's name public.