ROSEVILLE (CBS13) – It’s the investigation into his granddaughter’s death that investigators say lead them to Daniel McGrath’s extensive collection of child porn.

There were 3000 pictures and videos of victims as young as babies.

A woman at McGrath’s home told CBS13 she had no comment about the 58-year-old’s arrest.

It was in April that police came to their door; but, that time McGrath called them over.

He and his wife, who is out of the country, told police they needed to find their daughter Denise Wilder.

She hadn’t gone to work and they were worried about their two young granddaughters.

Inside, police say they found the drunk mother and her two-year-old daughter, Mckinlely Wilder, dead.

According to court documents, knowing they would seize his computers, hard drives, VHS tapes and CDs as potential evidence in his granddaughter’s homicide case, McGrath confessed to the child porn.

Police say what McGrath didn’t confess to though: allegedly hiding cameras in his own daughters’ rooms. Videos appear to be taken when they were teens, recording as one got dressed and before the other took a shower.

Police say he was able to keep his stash a secret for years.