DENVER (CBS4) – The Adams County district attorney has charged Denver Police Officer Timothy J. Kelley with sexual exploitation of a child, a felony, for allegedly downloading and keeping videos and files deemed “sexually exploitative material.”

Kelley, 49, who was with the Denver Police Department for 19 years serving as a detective and crime scene investigator, resigned late last week in the face of the child pornography investigation.

“He retired and is a former employee. There’s not much more we can tell you,” said Denver Police Cmdr. Matt Murray.

Kelley’s phone number is disconnected and CBS4 was not able to reach him or his attorney.

According to an arrest warrant affidavit obtained by CBS4, Westminster police were contacted in January by the Douglas County Sheriff’s Department which had been investigating online sharing of sexually exploitative material. Police said they found Kelley’s computer had been used to download child pornography, some of it featuring young boys having sex with adult men.

On May 21, Westminster police executed a search warrant on Kelley’s condominium. They say he arrived at the home while they were there and told them he lived alone but that his two 12-year-old daughters sometimes stayed with him.

Police say that when they advised Kelley of his Miranda rights, he said he had “no reason for me to talk to you right now”.

Authorities say they seized Kelley’s laptop computer and other electronic devices.

According to the arrest documents, police “located five video files on the computer that depicted prepubescent children, male and female, exposing their naked bodies and engaging in sexual acts with each other and with adults.”

The affidavit goes on to say that police found 894 downloaded files with titles consistent with sexually exploitative material. They say they found evidence there had been hundreds more files of sexually exploitative material that had been downloaded, but later deleted.

Court documents indicate Kelley was arrested late last week then released from jail on $5,000 bond.