He's an abuser of girls, and Mike isn't his name. He not only lies to Holder and Linden, but kidnaps Linden at knifepoint at the end of the episode. Holder's opinion of "Mike" is thus entirely justified. But when it comes to The Killing, we already learned in the first two seasons to expect a surfeit of suspects, some of whom are genuine bad guys, but only one of whom is the killer.
Who is the killer this season?
Linden is convinced it's not Ray Seward, the guy on death row, and he's certainly not the killer of this season's victim, whose circumstances of death are similar to the killing that led to Seward's death sentence. In one of the best scenes of the season so far, Skinner tells Linden he believes her about Seward's innocence, which almost reignites the passion they felt for each other when they worked Seward's case in the first place. (It's likely this feeling more than any else which is driving Linden not to want to have anything more to do with her former boyfriend on the island.)
One thing this season's The Killing lacks is the profundity of the impact of the killing on Rosie's family in the first two seasons. But Seward's death row story almost makes up for that, and the persistent sense that we're not seeing the killer even when all evidence seems to point that way is in good supply this year. Maybe there'll be an additional twist in which Pastor Mike turns out to be indeed be the killer. And he's obviously a creep and prime example of opium of the masses in any case. But I'm still putting my money on it's not him.
See also The Killing 3.1-2: Poe Poetic Po-po ... The Killing 3.3: Hitchcockian Scene and More
See also The Killing Season Two Premiere ... The Killing 2.2: Holder ... The Killing 2.11: Circling Back ... The Killing Season 2 Finale
And see also The Killing on AMC and The Killing 1.3: Early Suspects ... The Killing 1.5: Memorable Moments ... The Killing 1.6: The Teacher ... The Killing 1.8: The Teacher, Again ...The Killing 1.9: The Teacher as Victim, Again ... The Killing 1.10: Running Out of Suspects ... The Killing 1.11: Rosie's Missing - from the Story ... The Killing 1.12: Is Orpheus the Killer? ... The Killing 1.13: Stretching Television