Matt Koso of Falls City pleaded guilty and was convicted of first-degree sexual assault by Richardson County District Court Judge Daniel E. Bryan Jr. Tuesday.

“This case was not about two star-crossed lovers in a modern-day version of Romeo and Juliet," said Attorney General John Bruning. "This case was about a grown man having sex with a child. Mr. Koso committed a serious crime, and he must now face the consequences.”

Bruning filed one count of first-degree sexual assault against Koso, 22, in July after learning of his two-year sexual relationship with a 14-year-old girl who ended up pregnant with his child.

Under Nebraska law, it is a crime for people age 19 and older to have sex with people 15 and younger. The pair was married in May in Hiawatha, Kansas, where state law allows girls as young as 12 to marry with parental consent.

Judge Bryan offered to arrange for an evaluation of Koso’s “mental abilities” that could be taken into account at sentencing, but Koso declined.

First degree sexual assault is a Class II felony punishable by 1-50 years in prison. Sentencing has been set for Tuesday, Feb. 7, 2006.

Criminal Bureau Chief Don Kleine handled the case.

There are two similar cases pending in Douglas County.

Ontoniel David Perez-Garcia, 22, was arrested last month for first-degree sexual assault. Police say he's the boyfriend of a 14-year-old girl who miscarried.

Earlier this month, police also booked 21-year-old Jorge Narciso-Resendiz for sexual assault.

A hospital called police after a 16-year-old gave birth.

Police accuse him of having had a sexual relationship with the girl since she was 15.