LOCKPORT – A Town of Tonawanda man, who kidnapped a 5-year-old girl from her North Tonawanda home last summer and sexually abused her, pleaded guilty Thursday after a judge said she probably would have allowed prosecutors to tell a jury about past similar crimes.

David J. Grover, 35, of Niagara Falls Boulevard, agreed to take a 15-year state prison sentence followed by 25 years of probation-like post-release supervision. Niagara County Judge Sara Sheldon Farkas will make it official April 30.

Grover pleaded guilty to second-degree kidnapping as a sexually motivated felony. The sexual aspect lengthened the post-release supervision period and also forced him to register as a sex offender after he is released from prison.

The girl’s great-grandmother told reporters that was important “so he can’t hurt anyone else.”

The incident occurred in the predawn hours July 28. Assistant District Attorney Robert A. Zucco said it was obviously a sexually motivated crime.

“What other reason does he have to take a 5-year-old girl from her home in the middle of the night?” Zucco asked in court.

Zucco said if the case went to trial, he and Deputy District Attorney Holly E. Sloma should have been allowed to tell jurors about Grover’s 2007 conviction for taking another North Tonawanda girl on a car ride for several hours without permission. There was no evidence of sexual abuse in that case, but Zucco said, “It was a remarkably similar offense.”

Defense attorney David C. Douglas said allowing that would sink Grover’s hopes of acquittal.

“I think the prejudicial impact is insurmountable. The trial is over before it starts,” Douglas said.

Zucco also said he wanted to introduce evidence about a 2004 conviction for attempted burglary in which Grover entered a Town of Niagara residence, nude from the waist down.

Zucco said Grover told his mother he was on cocaine when he took the girl in 2007. “This is this guy’s fallback argument,” he said.

Farkas said she was inclined to let prosecutors introduce information about the earlier incidents and asked if there was a chance of a plea right away. Douglas asked for time to talk to Grover, and the deal was worked out in about half an hour.

In another sex case Thursday, Farkas told a Wilson High School 10th-grader she will deny him youthful-offender status and send him to state prison for molesting a 5-year-old girl in Cambria between October 2011 and the spring of 2012.

Thomas E. McGrew Jr., 17, of Maple Road, was scheduled for sentencing Thursday, but it was postponed until April 25. Assistant Public Defender Michael E. Benedict asked for the delay so McGrew could serve as much of his sentence as possible in the County Jail.

McGrew faces up to four years behind bars. Farkas said he also will receive 10 years of post-release supervision.

Also Thursday, Brett E. King, 47, of 65th Street, Niagara Falls, was allowed to plead guilty to endangering the welfare of a child for “inappropriate physical contact” with a girl under age 11 between September 2010 and December 2011.

King originally faced a sex crime indictment that could have landed him in prison for 21 years, but now the maximum will be one year when he is sentenced May 22.

Zucco said it was “a one-witness case with a child being the witness.” He said he offered the plea because of “the proof problems and to prevent the child from having to testify in open court.”