The trial of a Colwyn police officer charged with improperly arresting and Tasering a 16-year-old detainee opened Thursday, with much of the testimony dancing around some difficult gray areas.

Where is the line between obscenity and threat? And if a police handbook doesn't expressly prohibit action, where do you draw the line?

Cpl. Trevor Parham is accused of improperly arresting Da'Qwan Jackson on April 23, and later using a stun gun on the teen while handcuffed and shackled in a holding cell.

Parham waived his right to a jury trial, so his case will be decided by Delaware County Common Pleas Court Judge Kevin R. Kelly.

Parham, 40, is charged with simple assault and two counts of official oppression - one for arresting Jackson and one for using the stun gun.

The alleged victim and his mother testified, followed by Officers Derrick Taylor and Jade Hayes, acting Chief Wendell Reed, and Detective Thomas L. Worrilow, the special investigations unit officer who launched the inquiry.

Jackson, who has had numerous run-ins with the police and is on probation, says he was handcuffed and shackled from the moment he entered the cell. Parham reported that Jackson was only "secured" after he became belligerent in the cell.

Jackson, picked up for disorderly conduct, admitted yelling and kicking at the bars and lobbing profanities at Parham.

Whether his actions justified Tasering is disputed. Under department policy, stun weapons cannot be used on subjects who are "passively resistant."

"How much more passive can you get than when you're shackled in a cell?" Worrilow said under questioning by the defense attorney.

Reed said he did not believe the Taser use was inappropriate, given Parham's assertion that the teen was "on his way" to hurting himself or damaging the cell.

Hayes, who said she was in a romantic relationship with Parham at the time, said she received a text message that night saying he had arrested an unruly teen who "got tased in the cell, LOL."

Parham did not report his use of the Taser, as policy requires. Reed said he did not find out about the incident until after a subordinate took the allegations to the mayor and the investigations unit.

Contact Jessica Parks

at jparks@philly.com or 610-313-8117.