Jakubowski is facing three felony charges in connection with the gun store burglary and could be sentenced to more than 20 years in prison if found guilty.
Following opening arguments, the jurors watched startling surveillance video.
Rock County Sheriff's Detective Ronald Betley, a witness for the prosecution, said the video showed Jakubowski smashing the front door of the gun store with a hammer.
The man in the video can then be seen kicking the front door and diving into the store.
Betley said the man in the video, believed to be Jakubowski, ripped several long guns off of a wall and cleared out handguns from a glass case.
Prosecutors claimed he also made off with ammunition and magazines.
When Jakubowski was captured five days later, Betley said the serial numbers of several weapons in his possession matched those of the guns stolen in Rock County.
"We had a lengthy interview with Mr. Jakubowski," Betley said. "He freely admitted that he was the one that broke into the gun store and stole the firearms."
Some of the firearms taken are still missing.
Late last year, Jakubowski was found guilty in federal court and sentenced to 14 years in prison for stealing firearms and silencers from a federally-licensed dealer and being a felon in possession of firearms and silencers.