Reno, Nev. ? The 21-year-old college art student accused of putting pipe bombs in mailboxes in five states told authorities he was trying to make a “smiley face” pattern on the map, a sheriff said Thursday.

The first 16 bombs were arranged in two circles, one in Illinois and Iowa and the other in Nebraska. On a map, the circles could resemble the eyes of the popular 1970s happiness symbol. The final two bombs, found in Colorado and Texas, form an arc that could be the beginning of a smile.

“There was a comment made to one of my officers about his hope to make a smiley face when he was all finished,” Pershing County Sheriff Ron Skinner said.

Skinner said Luke Helder made the comments to an undercover county officer shortly after his arrest Tuesday outside Reno.

“His demeanor was very jovial. He didn’t seem to be taking anything seriously at the time,” the sheriff said.

An FBI official would not comment on the sheriff’s report.

Meanwhile, Helder’s parents, Cameron and Pamela Helder, met with their son at the county jail in Reno for a half-hour. They were separated by glass and spoke by telephone.

“We are here to see our son in his hour of need,” Cameron Helder told reporters afterward. “We told him we love him. I feel a lot better after speaking to him.”

Helder faces federal charges in Illinois, Nebraska and Iowa, where he will be taken today for an initial court appearance. U.S. Magistrate Robert McQuaid Jr. denied a request Wednesday to release Helder to the custody of his parents.

“It’s apparent to me that he suffers from some apparent mental health problems,” McQuaid said.

If convicted, Helder could be sent to prison for life. Cameron Helder said he expects the legal proceedings to be a long process.

The FBI said Helder placed 18 pipe bombs in mailboxes in Iowa, Illinois, Nebraska, Colorado and Texas, along with anti-government notes. Six of the bombs exploded last Friday, injuring four letter carriers and two residents.