Kevin "Kayvon" Edson, 25, was arraigned in Boston Municipal Court on charges of possessing a hoax explosive device, threatening battery, threats to commit a crime, disturbing a public assembly and disorderly conduct, according to the Suffolk district attorney's office. Bail was set at $100,000 and a judge ordered that Edson be evaluated at a state psychiatric hospital.
According to a police report read aloud in court Wednesday, Edson told an officer: "I knew what I was doing, it was conceived in my head. It's symbolism, come on. The performance got the best of me."
His mother said he suffers from bipolar disorder, and his lawyer, public defender Shannon Lopez, said he was diagnosed with mental illness at 19. A doctor said Edson showed signs of being off his medication recently, Lopez said.
"Our family is so sorry and emotionally overwhelmed by the events at the finish line of the Boston Marathon yesterday," Joie Edson said. "Our son Kevin has been battling mental issues for several years. His illness has caused himself and our family years of anguish that is unimaginable."
Police officers approached the man late Tuesday after noticing suspicious behavior, such as walking barefoot down the middle of the street in pouring rain and veiled in black, police Superintendent Randall Halstead said.
"As he got closer, I could hear him yelling 'Boston strong. Boston strong,'" witness Alicia Anskis said. "Something just felt really off."
Officers found a rice cooker in the backpack and told Edson to drop the bag. He was then arrested. Last year's deadly bombings that killed three people and injured more than 260 others were carried out via pressure cookers.
A bomb squad was called in and the area evacuated, before police blew up the backpack. Turns out, only confetti was inside.
Police blew up a second suspicious bag on Tuesday night. It was later determined the bag belonged to a media outlet and was not a danger.
The two incidents occurred after various ceremonies during the day honoring victims and first responders of the Boston Marathon bombings last year.
Despite the scare, marathon organizers said next Monday's race will be safe.
ABC News and The Associated Press contributed to this report.