The Pittsburgh police released a statement on the alleged incident, via Bob Hazen of WTAE-TV:

At approximately 9:30 p.m., security guards at The Flats on Carson summoned a Pittsburgh Police Officer who was working at a nearby restaurant due to an unruly customer who was in the process of assaulting the doorman. Once he arrived on the scene, the Officer stopped the assault and arrested the actor, identified as 39-year-old Pittsburgh Steelers assistant coach Joey Porter. Porter was taken to the Allegheny County Jail. His charges include aggravated assault, simple assault, public drunkenness and terroristic threats.

On Wednesday, the Associated Press (via Fox Sports) provided additional insight into the situation:

Review board executive director Elizabeth Pittinger says the 'high visibility' of the incident prompted the review, even though the board typically doesn't investigate unless someone complains about police misconduct. Porter's attorney says they didn't file a complaint about the officer's conduct.

Acting police Chief Scott Schubert says video he's reviewed of the incident supports Officer Paul Abel's version of events and justifies the arrest. Abel says Porter grabbed him by the wrist after he went to break up a dispute between Porter and a bouncer, hours after the team's playoff win over the [Dolphins].

On Thursday, WPXI in Pittsburgh reported the district attorney would pursue disorderly conduct and public drunkenness charges only, with the other charges being withdrawn. 

Michael Sanserino of the Pittsburgh Post-Gazette shared Porter's mug shot:

Michael Sanserino @msanserino

Joey Porter's mug shot.

Chris Mueller of the Beaver County Times first reported on the arrest.

On Jan. 8, Joe Rutter and Megan Guza of the Pittsburgh Tribune-Review passed along a statement from Burt Lauten, the team's director of communications:

Megan Guza @meganguzaTrib

Team statement via @tribjoerutter

Porter was placed on leave on Jan. 9 while the Steelers continue to investigate the incident, per Mike Garafolo of NFL Network.

Steelers head coach Mike Tomlin spoke with reporters on Tuesday, saying it was "disappointing" and that "to be involved in NFL is a privilege and not a right." Tomlin added that there is no timetable for Porter's leave of absence.

Tomlin noted that there have been no changes as to who coaches the outside linebackers while Porter is on leave.

On Monday, Steelers offensive lineman David DeCastro told reporters that Porter's arrest won't be a distraction, saying that the team is "locked in."

Porter has been an assistant coach with the Steelers since 2014, following his 13-year playing career.

He last made national headlines for his role in an altercation during a playoff game between the Steelers and Cincinnati Bengals. During the AFC Wild Card Round matchup in January 2016, the coach took the field and argued with Bengals cornerback Adam Jones, drawing a fine.

The NFL responded by making a new rule banning assistant coaches from entering the field of play.

Porter spent the first eight seasons of his playing career with the Steelers, earning three of his four Pro Bowl selections. The former linebacker totaled 98 sacks during his time in the league, also recording 12 interceptions.

Pittsburgh is set to face the Kansas City Chiefs in the second round of the playoffs this coming Sunday.