MARTINEZ (CBS SF) — Police were investigating a New Year’s Day bombing that left a long-time downtown sports-memorabilia store in shambles.

Store owner Steve Lipary said that early Friday morning a man on a motorcycle attached an explosive device to a store window at LC Galleries sports and celebrity memorabilia shop on Main Street and then drove away as the device blew a hole in the window.

“This was a homemade device,” Lipary said. “It blasted glass 50 feet to the back of the store, there was glass everywhere.”

Lipary spent Friday cleaning up the strewn glass and debris, which also damaged some frames, artwork and memorabilia inside the store.

“It was a mess,” he said.

He said he also reviewed the store surveillance tapes and saw that at 4:30 a.m. Friday a motorcycle pulled up to his store and the rider got off.

Lipary said the man taped what looked like a small package to the window. The surveillance tape shows the rider lighting a large fuse and then speeding off.

Police told Lipary they believe it was fireworks of some type that caused the explosion. They also said the motorcycle was stolen from Pleasant Hill.

Anyone with information about the crime is asked to call Martinez Police.