When federal agents searched Mark W. Wolfe's computer, they recovered 486 videos and 203 images of preteen girls and boys displaying their genitals and in some cases having sex with adults.

When federal agents searched Mark W. Wolfe's computer, they recovered 486 videos and 203 images of preteen girls and boys displaying their genitals and in some cases having sex with adults.

Authorities said those weren't the worst discoveries.

Wolfe, 50, a former Delaware County Sheriff's deputy who served as interim sheriff for five days in 2007, pleaded guilty Thursday, March 10, in U.S. District Court to one count of distribution of child pornography. The charge carries a maximum 20-year prison term. The plea agreement worked out by prosecutors and the defense calls for a prison term ranging from 12 to 17 years.

The investigation began in June when an FBI agent conducting an online investigation noticed someone downloading videos of a girl, estimated at 10 to 12 years old, having sex with an adult. Another video involved a baby.

The agent traced the user to an Internet address at Wolfe's Sunbury home. The original three-count complaint said the agent traced Wolfe's activity back to November 2012.

Wolfe, who became a deputy in 1994, was fired by then-Sheriff Al Myers in 1997 for allegedly sexually harassing a female employee. Wolfe ran for sheriff in 2000 and 2004, losing both times to Myers.

Three years later, Myers resigned as sheriff amid ethics charges. Wolfe briefly was brought back as interim sheriff. Soon afterward, he investigated Myers for pornography found on Myers' computer.

A new sheriff was elected and Wolfe's association with the Delaware office ended. He then ran a security firm and served as assistant police chief in Edison.

Myers sued Wolfe and the county for defamation and settled for $125,000. Then-Delaware County Prosecutor David Yost determined the pornography on Myers' computer was part of a legitimate criminal investigation.

A presentencing report must be conducted in the federal case before Wolfe's sentencing date is set.