Middlesex County prosecutors did not file criminal charges against Wakefield child care provider John Burbine in 2005 and 2009 in part because the victims and their families were “unwilling or unable’’ to provide enough cooperation to give prosecutors confidence that they would win convictions.

“We did not have the evidence we needed to sustain criminal convictions due to a variety of factors, including the fact that the victims and their families were unable or unwilling to go forward,’’ said Stephanie Chelf Guyotte, a spokeswoman for Middlesex District Attorney Gerry Leone.

The same was true of a child sexual abuse complaint referred to prosecutors by the Massachusetts Department of Children and Families near the end of June, the third and last time the agency alerted prosecutors to allegations against the 49-year-old Burbine.


But in that case, Chelf Guyotte said, prosecutors discovered that Burbine and his wife, Marian, were operating an unlicensed Wakefield day care business, the Waterfall Education Center.

And while investigating the business, prosecutors obtained a warrant to search the Burbine’s home, where they discovered the evidence that led to Thursday’s 100-count indictment charging Burbine with sexually abusing more than a dozen children ranging in age from eight days old to 3 1/2 years old, in some cases filming himself sexually abusing the children.

Then, in September, after discovering the evidence, prosecutors quietly charged Burbine with two counts of rape of a child and 13 counts of possession of child pornography, as they continued to build the larger case they unveiled Thursday.

“After the arrest was made to alleviate any public safety threat, our office continued its thorough investigation which uncovered more than a dozen victims,’’ Chelf Guyotte said, adding that prosecutors used the intervening three months to identify the additional victims and provide them with information and counseling. “Identifying and working with victims was our priority during that time,’’ Chelf said.

Prosecutors charged Marian Burbine with reckless endangerment of a child and operating an unlicensed day care business on Oct. 1. She was released on bail, confined to her home between 6 p.m. and 8 a.m., and ordered to wear a GPS monitoring devise.