Maria Carrillo student Keith Lutter, 15, remained at Children's Hospital Oakland on Tuesday, more than a week after he was found seriously injured on the ground at Montgomery High School.

Lutter, who suffered head injuries in what police said was likely a fall, has been in an induced coma as part of his care.

Police still are investigating what happened that Nov. 23 afternoon. He was found unconscious and bleeding, lying alongside an outer gym wall.

"Nothing has developed. We're still not able to talk to him because of his condition," said Santa Rosa Sgt. Dave Linscomb on Tuesday. "More than anything, things seem consistent with a fall."

Police have said they've learned the teen has been on Montgomery's roof at least once in the past and has been known to participate in a sport known as parkour.

Parkour involves scaling, leaping and performing other acrobatics using everyday obstacles such as railings, walls and sometimes roofs as a course.

If Lutter was scaling a wall or jumping from roof to roof at Montgomery when he was hurt, he's not alone in getting injured during such an activity.

Detectives have interviewed a teen who broke a leg while roof jumping at Montgomery in recent months. The two injured boys know each other, Linscomb said.

Montgomery High officials did not return a phone call seeking comment Tuesday.

Santa Rosa fire Capt. Steve Lowe said he's been to three schools for calls regarding teens injured while roof jumping. One was at Montgomery.

"I've been to three of those in the last six months, kids getting injured on the roof," Lowe said. "These kids had been jumping from roof to roof."

That kind of stunt would be a high-level move rarely performed by people who actually practice parkour, said Brett Robert, a parkour coach with Flying Frog Freerunning in Rohnert Park.

"As a general rule we don't go up on rooftops," Robert said. "There's more than enough stuff to do at ground level, and you should have your technique perfected at ground level before you go up even a foot."

High school-aged boys are a core group of the 70 students Robert teaches at the Rohnert Park Gymnastics facility on Professional Center Drive. Robert said he did not know Lutter and hadn't heard from anyone in the parkour community who did.

Robert said his program follows the World Freerunning and Parkour Federation's curriculum that moves students through five levels of skills. They might spend weeks on one move, such as learning to safely jump from one two-foot tall concrete planter box to another.

"The small incremental progressions that we teach are the best way to combat that tendency to think they can try some amazing stunt they saw on YouTube," Robert said.

It wasn't clear whether any recent incidents of students injured after climbing onto school roofs involved youth trying to emulate stunts.

At Montgomery, firefighters used a ladder truck to get to a boy on the roof, too injured to get down.

"We had to use the aerial ladder to lower one down. They'd hurt their leg," Lowe said.

Another call was to Spring Creek Matanzas Charter School campus on Yulupa Avenue.

At that elementary school, a boy suffered injuries that left him at least temporarily immobilized.

"He couldn't move. He couldn't walk. He was on the ground. I don't know whether he'd gotten to the ground (or fallen,)" Lowe said.

Lowe couldn't recall the location or details of the first school call. All of the calls occurred during the summer or after school hours.

He said the three injured males were taken to hospitals by ambulance. Lowe estimated the teens were 14 to 17 years old.

Police also are familiar with calls regarding teens on school roofs.

"It's pretty common. We actually get that call a lot," said Linscomb. "Not just at Montgomery but at different schools."

The calls typically involve reports of kids sometimes hiding, sometimes jumping from roof to roof; sometimes it involves vandalism, he said. "Usually it's fairly benign."

"Look at the roof lines of a lot of schools. It's all connected with breezeways ... You can get from one end to another without ever coming down," he said.

Staff Writer Julie Johnson contributed to this report. You can reach Staff Writer Randi Rossmann at 521-5412 or randi.rossmann@pressdemocrat.com.