WASHINGTON, July 29 (Xinhua) -- U.S. President Donald Trump on Monday condemned the shooter who opened fire at a garlic festival in Gilroy, California on Sunday, killing three and injuring at least 15 others.

Speaking before a bill-signing ceremony at the White House, Trump called the perpetrator, identified as 19-year-old Santino William Legan, "a wicked murderer," while promising efforts to "stop evil" and "prevent violence."

The president also said that the nation would grieve for the families of the victims and prayer for those who are recovering in the hospital.

The shooting took place Sunday evening at Christmas Hill Park in Gilroy, a city about 130 kilometers southeast of San Francisco.

The gunman used a tool to "cut through the fence to gain access to the security fence line" and entered the grounds of the festival before shooting randomly into the crowd with a rifle, according to authorities.

Police responded within a minute and killed the gunman.

Among those killed by the gunman was a 6-year-old boy.