The trial of the suspected assailant, previously identified only as a 33-year-old Yemeni resident, had begun, the broadcaster added.
The Nov. 11 attack occurred at King Abdullah Park, one of several venues hosting a months-long entertainment festival as part of government efforts to open up Saudi society and diversify its economy away from oil.
It sparked fears of a potentially violent backlash in the ultra-conservative Muslim country against social reforms implemented by Crown Prince Mohammed bin Salman, including ending bans on women driving, gender segregation and public entertainment.
The victims of the attack, two men and a woman, sustained “superficial wounds” and were stabilized after receiving medical care, state media reported at the time.
Saudi Arabia intervened in Yemen’s civil war in 2015 against the Iran-aligned Houthis. The U.S.-backed military coalition it leads also carries out operations against al Qaeda’s Yemen branch known as al Qaeda in the Arabian Peninsula (AQAP).