The former couple abruptly married in 2004 following a short relationship. Less than three days later the marriage was annulled after claims that Spears did not fully understand her actions.
According to TMZ, Alexander was arrested on December 30 and charged with violation of a protective order and aggravated stalking.
On January 4 he was handed 11 months and 29 days of probation in exchange for pleading guilty to misdemeanour stalking. He was also told to undergo a mental health screening and ordered to submit to random drug tests. Alexander will also not be permitted any contact with the unspecified victim.
Spears has been in a relationship with her fiance Sam Asghari since 2016.