-- From Times staff reporter Jennifer Sullivan:

A Seattle lawyer who scratched three vehicles with his keys because he was angry with the drivers' parking skills pleaded guilty Thursday inside a Seattle courtroom.

Soon after Ronald Clarke Mattson was charged with second-degree malicious mischief, a felony, his lawyer put out a statement saying that his client had "expressed his great remorse and shame for what he did." He pleaded guilty Thursday to a reduced count of attempted second-degree malicious mischief, a gross misdemeanor. He cried during the hearing and answered Judge Beth Andrus in a shaky voice.

Prosecutors asked for a one-year suspended sentence, restitution for the three victims and an anger-management class for Mattson, who has already paid nearly $10,000 in restitution and attended the classes.

"I have already taken the steps to become a better person," Mattson told Andrus in court.

The judge then sentenced him to a one-year suspended sentence and 240 hours of community service.

Mattson, 63, was caught in the act by Columbia Center security staff during a sting operation after two people reported their vehicles had been "keyed" March 9 and 11, according to charging documents.

In both incidents, the vehicles were parked over the designated parking-space lines. In addition to the damage, insulting notes were left on the windshields criticizing the drivers and calling them "dweeb" and "idiot," according to charging paperwork filed by King County Senior Deputy Prosecutor Mary Barbosa.

When one of the victims contacted staff at the building, security staff at the high-rise hatched a plan to catch the culprit.

On the morning of March 15, security staff parked a "bait" car in the garage so the vehicle straddled the lines of two spaces and had a surveillance camera pointed toward the bait car. A security officer then climbed inside another car parked nearby and waited, charging paperwork said.

Mattson drove past the set-up in his silver Porsche, then backed up before driving away. Mattson quickly reappeared and walked up to the bait car.

When Mattson reached the corner of the passenger side of the bait car, his "hand and arm rose up slightly away from his body" and appeared to be scratching the car with his keys, charges said.

Surveillance videos showed Mattson keying the bait car, as well as images of the lawyer parking his Porsche near the other two vehicles that were damaged.

While Mattson initially denied causing more than $6,000 damage to the three cars, he later told detectives that he had scratched the cars and left the two notes, Barbosa wrote in charging documents.

Mattson, whose office is in Columbia Center, has been a lawyer since 1972. His lawyer, Matthew Honeywell, said he could also face punishment from the Washington State Bar Association.