It's learned that NBC has not ordered a full season for Constantine.
Deadline reports that NBC has not ordered additional episodes past the initial 13.
Constantine is slated to stop production with episode 13, which ironically enough will feature the return of Jim Corrigan.
Corrigan and The Spectre (played by Emmet J. Scanlan) recently debuted on Constantine to high ratings, which saw a 38% bump.
In the report about the stop in production, it does mention Constantine is still in contention for a second season.
One reason given for the stoppage is that NBC had "little ratings information," which made the decision regarding continuing production apparently a difficult one.
It's also said that NBC does seem to be behind the series as re-runs of Constantine are airing on their cousin network, SyFy, and cast members are set to appear on NBC's Macy's Thanksgiving Day Parade this week.
To add my own two cents to the story, having Constantine air Friday nights at 10pm ET was an uphill battle from the start.
As the report also notes, Constantine was one of three new DC drams that premiered this Fall. Both Gotham (on Mondays) and The Flash (on Tuesdays) have received full-season orders, while Constantine has not.