A Keelung man serving life for smothering his 5-year-old son has twice mailed threats to his ex-wife's family from behind bars, and the family has now won a protection order.

• The man, a former Keelung environmental bureau driver, was given life in prison in April after a citizen-judge court found he killed his son during a custody dispute.
• In June he wrote from Keelung Detention Center threatening to wipe out his ex-wife's entire family, prompting a police report and a transfer to Taipei Detention Center.
• He sent a second round of threats anyway, this time using veiled language about ghost month and "heaven collecting" his ex-wife.
• He got the letters out by addressing them to a friend, hiding who the real recipient was and dodging inspection.
• Detention rules only allow staff to check mail for contraband, not read every word, unless an inmate has already broken the rules.

Outlook: Taipei Detention Center says it will tighten screening of his mail, and the family is weighing a second criminal complaint on top of the prosecutors' new intimidation case.