An episode in Season 2 featuring Morgan Freeman discusses experimental models for human death .
The killer is revealed to be Ryan Smulson , the seemingly clumsy and eager police intern. [S2E10] The Hour of Death
The episode explores the dark history of Nick's ancestors (the Endezeichen ) and how their legacy of brutality still haunts the present. An episode in Season 2 featuring Morgan Freeman
The police department is compromised from the inside by an intern who uses his access to stalk and manipulate the lead detectives. Other Possible References The police department is compromised from the inside
Season 2, Episode 10 is titled "No Weddings and a Funeral," but it is often discussed in the context of "Love and Death" due to the death of a major character's father.
If you were referring to a different "[S2E10] The Hour of Death," there are a few other possibilities, though Grimm is the most prominent:
Analyze Ryan's psychological state. He is a Wesen who wants so desperately to be a "heroic" Grimm that he becomes a monster to his own people.