Officers have been on the lookout since summer for a man on a bike who has been smacking women on their rear ends. View Full Caption DNAinfo/Patty Wetli

LINCOLN SQUARE — Reports of a man on a bike groping women go back to before incidents reported in September, but efforts to catch the guy have failed, according to Lincoln Police District Cmdr. Sean Loughran.

Speaking at a recent districtwide CAPS meeting, Loughran said his officers have been on the lookout for the suspect since the summer.

"We've done a ton of stuff to grab this guy," Loughran said, including stopping all cyclists in violation of the prohibition against riding on the sidewalk.

Police have also biked the path in River and Legion parks, where a number of groping incidents have been reported, he said.

The challenge has been that the attacks stop and start sporadically, Loughran said, which makes it difficult to predict when or where the guy will strike.

Women have complained that the use of the term "groping" to describe the incidents trivializes the crime. An attendee at the meeting asked the commander to clarify "groping" versus "sexual assault."

Loughran said that "groping" — the man on the bike typically rides up behind women and smacks them in the rear — would qualify as "battery."

According to Illinois law, criminal sexual assault involves "an act of sexual penetration."