The cuffs go on Tyler in Thursday's Fair City on RTÉ One and the RTÉ Player.
The drama begins when Fidelma and Buckley discover Tyler's elaborate obsession wall and move to arrest him.
As Laura's memorial gets under way, Fidelma arrives and says: "Tyler Monroe, I'm arresting you on suspicion of the murder of Laura Halpin and the arson attack on Damien Halpin."
Fans can find out what happens next on Thursday on RTÉ One and the RTÉ Player at 8:30pm.
Fair City airs on RTÉ One and the RTÉ Player on Sundays, Tuesdays, Thursdays, and Fridays.
