Mark Francis Roberts (search) learned the naked truth about Texas justice Monday.

Roberts, 39, was found guilty of misdemeanor trespassing for his on-field streak during the Super Bowl (search) on Feb. 1, as a six-woman jury turned aside his lawyer's contention that he didn't receive proper notice that he wasn't allowed on the field.

"The whole reason I did it was to entertain people, America," said Roberts, a Brit who has pulled similar stunts abroad more than 300 times but incurred his first conviction with his first U.S. streak. "If making people laugh is a criminal offense, I should be sentenced to prison for life."

Fortunately for Roberts, who lives in Liverpool, England (search), the Class B misdemeanor carries a maximum sentence of six months in jail and up to a $2,000 fine. The jury, which took an hour to deliberate, will return Tuesday to consider punishment arguments.

Roberts, who dropped to the Reliant Stadium field and galloped onto the field in a faux referee's costume then stripped to a football-shaped codpiece before dancing a jig, was not charged with anything besides criminal trespassing.

The better-known halftime incident occurred during the musical show when singer Janet Jackson's (search) right breast was exposed on worldwide television. Most of the packed stadium didn't notice that, but they did get an eyeful of Roberts as he strutted for nearly a minute before getting tackled by a player and arrested by Houston police.

The Internet gaming company that sponsored Roberts' performance carries images of the incident on its Web site and Roberts does the same on his own online page, www.thestreaker.org.uk.

Roberts and defense lawyer Sharon Levine, who works for famed attorney Richard "Racehorse" Haynes, argued no one told Roberts he was not allowed on the field and that a knee-high barrier in front of his front-row seat was no indication he shouldn't advance.

"There is no fencing to exclude intruders," Levine said during opening statements.

Prosecutor Kristin Guiney countered that while the NFL and Reliant Stadium had no signs or warnings on ticket stubs, the barrier and the sizable drop to the field made it obvious under the law even if there was no oral message, signage or ticket stub warning to the contrary.

"He had notice by virtue of that 6-foot wall (around the field) that his conduct and his presence on the field were forbidden," Guiney said.

Guiney called three witnesses: a policeman, a Reliant Park manager and an NFL security official. Levine rested without calling a witness and Roberts did not testify.