SUNBURY - A former substitute teacher at Shamokin Area School District charged with sending several sexually graphic text messages to four girls under the age of 18 is incarcerated at Northumberland County Prison after violating probation conditions set at his initial sentencing earlier this year.

Michael S. Zack, 25, of Marion Heights, who avoided jail time when sentenced by President Judge Robert B. Sacavage on Feb. 25, has been imprisoned since April 8 for violating probation conditions including using a cell phone to distribute 10 pornographic images of himself to two people.

According to a petition to revoke his probation, Zack possessed a cell phone and sent text messages between Feb. 25 and April 8 despite being prohibited from using a cell phone, web cam, computer or other electronic device providing Internet, audio/visual, written or other forms of communication.

Zack allegedly used the cell phone mobile applications "Instagram" and "KIK" to post photos and messages and the cell phone mobile application "MiuMeeet" to digitally contact other online users.

On April 8, county adult probation officers discovered one pornographic image of a female on Zack's cell phone mobile application "KIK." Zack allegedly received the image on April 4.

According to the petition, Zack also possessed six unused Suboxone medical strips on April 8 and failed to report the prescription to his supervising probation officer.

Efforts to reach Zack's attorney, Marc Lieberman of Elysburg, were unsuccessful Tuesday.

Re-sentenced

During a May 2 revocation hearing, Sacavage re-sentenced Zack on a felony of unlawful contact with a minor and misdemeanor of corruption of minors to six to 23 months in county jail followed by six months of house arrest. Following his house arrest period, Zack will be on parole for 11 months and then will be placed on probation for 2 years.

He also must pay all costs, fines and fees previously imposed and undergo a psychiatric evaluation and comply with any recommendations for treatment. All other probation conditions set at his first sentencing shall remain in effect.

Zack, who was given credit for time served between April 8 and May 2, has already completed more than 2 1/2 months of his sentence.

He pleaded guilty to the charges in December and was initially sentenced to three years of intermediate punishment and two consecutive years of supervised probation. He was ordered to serve the first six months of his sentence on house arrest that required him to wear an ankle bracelet, allowing authorities to monitor his movements. He also was required to pay $600 in fines plus various costs and fees.

Zack, who was ordered to begin his February sentence immediately, was prohibited from having contact with the victims and any other females under the age of 18 unless authorized by adult probation officials.

The judge imposed the sentence after reviewing a pre-sentence investigation report compiled by adult probation department employee Clifford Kinney.

Must register

Sacavage said an assessment by the Sexual Offenders Assessment Board determined that Zack is not a sexually violent predator, but reported adult probation department employee Clifford Kinney found the defendant to be suffering from sexual compulsion.

Although he was not deemed a sexual violent predator, Zack still must register his residence and employment with state police for the next 15 years in accordance with the Adam Walsh Act. He also was ordered by Sacavage to complete a sexual offenders course.

Zack was charged March 15, 2012, by Coal Township Detective Jeff Brennan with sending approximately 4,300 text messages to two 17-year-old females and two 16-year-old girls who attended Shamokin Area at the time. Many of the messages, which were sent between March 15 and Oct. 30, 2011, depicted sexually graphic material, police said.

Police said the incidents occurred in the east end of the township and at Shamokin Area Middle/High School.

A misdemeanor count of sending obscene and other sexual materials was not prosecuted.

Prior to his guilty plea, Zack voluntarily signed an affidavit surrendering his teacher's license, which had been suspended.

Zack was hired as a 180-day substitute teacher in the district in August 2011 and terminated by the school board at its December 2011 meeting, retroactive to Nov. 16, 2011.