Are you familiar with how the latch operates? If so hold a screwdriver horizontally and press it down into the latch where the loop on the hood would usually enter... When the latch rotor closes behind it try to lift up... if the rotor turns freely and allows you to lift the screwdriver back out you'll need to replace the latch; if the rotor is missing the portion which is supposed to swing around and close the opening behind the screwdriver, replace the latch. If the rotor closes behind the screwdriver and does not open back up when you try to pull the screwdriver back up the inspect the loop on the hood (to ake sure it's not broken free and moving) and try lowering the hood stops a 1/4".
If you're not familiar with how the mechanism works... talk to a locksmith.
