CONVICTION IN CHILD SEXUAL ABUSE CASE - 26 September 2025

DELHI - Delaware County District Attorney Shawn J. Smith announced that Mark P. Archer, 40, of Sidney, New York pleaded guilty to 3 counts of Sexual Abuse in the First Degree, Class D Violent Felonies. Archer appeared before the Honorable Gary A. Rosa, Acting Delaware County Court Judge, on September 18, to enter his plea.

The defendant was previously indicted by a Grand Jury on 12 counts related to sexual abuse against minors on October 5, 2023. The indictment alleged that the defendant engaged in a course of sexual conduct against three victims who, at the time of the incident, were less than 13 years old. The conduct took place over a period of several years between 2013 and 2019. 

The case was scheduled for a two-week jury trial slated to begin on Monday September 22.  However, on Thursday September 17, 2025, the defendant appeared in Delaware County Court and pleaded guilty to 3 counts of Sexual Abuse in the First Degree, Class D Violent Felony Offenses. 

Prior to pleading guilty, the defendant admitted that during the winter of 2013, while in the Village of Sidney, he did subject a child to inappropriate sexual contact. 

The defendant also admitted that in April of 2016, while in the Village of Sidney, he did subject a second child to inappropriate sexual contact. 

The defendant also admitted that in the Summer of 2018, while in the Village of Sidney, he subjected a third child to inappropriate sexual contact. 

As part of the guilty plea, it was agreed that the defendant would be sentenced to 4.5 years of incarceration and 10 years of post-release supervision for the sexual contact that occurred in 2013.  It was further agreed that the defendant would be sentenced to 4.5 years of incarceration and 10 years of post-release supervision for the sexual contact with the child that occurred in 2016.  It was also agreed that the defendant would be sentenced to 4.5 years of incarceration and 10 years of post-release supervision for the sexual contact with the child that occurred in 2018.  These sentences will run consecutively, resulting in an aggregate sentence of 13.5 years in state prison and 30 years of post-release supervision. The defendant will also be required to register as a sex offender when he is released from state prison.   Additionally, the Court is expected to enter a full stay away order of protection prohibiting any contact with the victims.   

Assistant District Attorney Denise Kerrigan prosecuted the case on behalf of the Delaware County District Attorney’s Office. 

District Attorney Shawn Smith commended the thorough investigation conducted by the Sidney Police Department, and the tenacious efforts of Assistant District Attorney Denise Kerrigan. 

“I am grateful to our entire team that worked on this case including the Sidney Police Department, Safe Against Violence, Delaware County Child Protective Services, the Delaware County Attorney’s Office, and Assistant District Attorney Denise Kerrigan. This defendant remained at liberty, without being charged criminally, for nearly a decade after he had sexual contact with a child in the winter of 2013.  As a result of a thorough and comprehensive investigation, our team was able to secure this conviction which will finally hold the defendant accountable for the acts he committed so many years ago.  My office is dedicated to protecting children, and we will never stop fighting to hold defendants accountable. Every victim deserves justice.”  

If anyone has been sexually assaulted- even years ago- call the hotline at 607-746-6278.  

As are all persons accused of a crime, the defendant is presumed innocent unless proven guilty in a court of law.

Shawn J. Smith

District Attorney

Delaware County