A Nepean man who spent last summer looking for young girls on pathways in Ottawa's west end has admitted he's guilty of the seven sexual assaults he's charged with.

Brent McGrath, 24, has been in police custody since October after police set up a command post in Ottawa's Trend-Arlington Park near Greenbank Road to monitor a suspect wanted in several sexual assaults, involving victims mostly under the age of 15. The youngest victim was an 11-year-old girl.

The sexual assaults sent fear rippling through the neighbourhood where women and young girls admit they were afraid to leave their homes.

"We were scared . . . everybody was scared," said one mother.

"Like everyone, you assume it's never going to happen in your own neighbourhood . . . I'm glad they caught him because it was a worry around here last summer," said a female jogger, who never thought she'd need to be on the lookout for a sexual predator in her own neighbourhood.

A break leading to McGrath's arrest happened when an undercover Gatineau police officer, who was working on a different case, wrote down McGrath's license plate number when he fled the scene, shortly after assaulting a 28-year-old woman.

The information was passed on to Ottawa police, who started monitoring McGrath's actions the next day.

"His behaviour was very concerning," said Sgt. John McGetrick of the Ottawa police sexual assault unit.

In court on Monday, the Crown read police notes documenting the surveillance efforts. According to the notes, McGrath spent days watching nearby pathways and parks until he spotted his next victim.

Sixteen days later, McGrath grabbed a woman's buttocks and fled the scene. Ottawa police arrested him nearby.

McGetrick said the success of the investigation was due to information gathered on all fronts.

"The whole team from front line to specialized investigators and the community were part of this success," McGetrick told CTV Ottawa.

"Investigations like this can be long and exhausting. We require reasonable grounds to make an arrest and we use many different tools to ensure -- to make sure -- we have enough grounds to arrest a subject."

McGrath will now undergo a psychiatric assessment at the Crown's request to see if he should be deemed a long-term offender. If classified a long-term offender, McGrath will continue to be monitored after completing his sentence.

"It would mean that after he served his sentence that there would be a period of time that he'd have, like an extended parole period, where there would be enhanced treatment and supervision conditions imposed on him," said defence lawyer Michael Spratt.

The sexual assaults occurred shortly after McGrath returned home to Ottawa from attending the University of New Brunswick.

An acquaintance from school told CTV Ottawa McGrath had good grades and seemed to get along with everyone.

McGrath is expected to be sentenced in September.

With a report from CTV Ottawa's Natalie Pierosara