A lock includes a solenoid-operated striker unit (4) for capturing pin-bolts (9) of the shot bolt assembly (3) of a key-operable locking mechanism (1) of a hinged door (2). The pin-bolts (9) are captured within a keep channel-member (13) that slides up and down within a fixed channel-member (10) between an upper, release position in which slots (14) in the member (13) are in register with slots (11) in the member (10) and a lower, locking position in which the slots (14) are out of register with the slots (11). The member (10) is set perpendicularly to the general plane of swing of the door (2), the pin-bolts (9) being free to move into and out of the channel-member (13) through the aligned slots (11,14) when that member has been lifted into its release position by the solenoid (17) or a manually-actuable lever (27). A catch (19) latches the member (13) in this position untii released, allowing the member (13) to move to its locking position under spring action, in response to entry of the uppermost pin-bolt (9) into the striker unit (4). According to a modification a catch (31) is released by a forwardly-offset pin-bolt (32), and a keep member (30) slides up and down behind an apertured bar (29) rather than within a channel member. Also according to an alternative, a solenoid-lifted cylindrical keep-member (41) rotates about its longitudinal axis in admitting pin-bolts (44) to, and releasing them from, axially-directed slots (46) that capture the pin-bolts (44) when the member (41) moves downwardly under resilient bias.