Vancouver police on Thursday evening arrested a man on suspicion of indecent exposure outside Marshall Community Park.Alan F. Wahl, 54, of Vancouver was booked into the Clark County Jail on suspicion of indecent exposure and resisting arrest, said Kim Kapp, Vancouver Police Department spokeswoman.James M. Smith Sr. said he spotted Wahl sitting in a red sedan outside the park masturbating with a blanket over his lap. Smith, who takes his 9- and 13-year-old boys to the park on a daily basis, called 911 to report the incident.“My first instinct was to go kick in his door,” Smith said. “I’m glad I didn’t do that in hindsight.”Vancouver police Officer Brian Ruder arrived and, once he verified what was going on, tried to get Wahl out of the car, Kapp said. Ruder eventually pulled the man out of the vehicle, and the man was handcuffed after officers used a Taser device. Two other officers responded.Wahl was taken to a local hospital for treatment of a scrape to the head, Kapp said, and then taken to jail.Around 30 kids and 12 parents were in the park at the time, according to police reports.Smith said he’s seen some strange activity in the park but nothing like that. “It was a very sick feeling,” he said of the situation. He said he’s glad police were able to respond and added that he’ll be vigilant in the future.“Our park will be safe this weekend, that’s for sure,” he said.