A Westport online market research executive has been charged with possessing child pornography after State Police raided his home last week and found the images on his computer, authorities said.

Kevin Hill, 47, of 31 Rayfield Road, was charged with first-degree possession of child pornography. Hill, who turned himself in to Westport police Friday, was released after posting $50,000 bond. He is to be arraigned Friday on the felony charge at Norwalk Superior Court.

An investigation of Hill began Dec. 15 after a trooper working at the State Police Computer Crimes and Electronic Evidence Laboratory determined that video files of suspected pornography were being shared from an Internet account assigned to Hill's Rayfield Road address, according to the arrest affidavit said. The affidavit said one of Hill's computers had a peer-to-peer file-sharing program that allowed his computer to connect to other computers with the same program and download videos and other images.

This allowed anyone with the file-sharing program to obtain images of child pornography through a keyword search. After the trooper found the files, a search warrant for Hill's home was obtained. State and Westport police went to Hill's home at 6:15 a.m. April 5 and seized six computers and three other items.

While the search was under way, Hill, who is a vice president for an online market research firm in Stamford, was interviewed by a trooper and Westport Detective Sereniti Dobson.

During the interview, Hill said he downloaded pornography and music through a file-sharing program he installed four years ago, the affidavit states.

A preliminary review of Hill's desk-top computer revealed there were 18 videos totaling more than an hour of "obvious" child pornography, the affidavit said.

The children depicted in the videos ranged in age from about 2 or 3 to about 12 or 13, the affidavit said.