Clay Maxwell

Clay Maxwell is the former partner and ex-best-friend of Captain Lou Grover. Grover suspects that Clay is responsible for the death of his wife upon discovering his year long affair.

Season 6
In the episode "Umia Ka Hanu" (Hold The Breath") Lou takes Clay captive in his own home and ransacks it in order to find the evidence that he stole $250,000 from a bust they did years ago since he cannot prove Clay murdered his wife.

Season 7
The only mention of Clay Maxwell in Season 7 is Episode 21 where Captain Lou Grover goes back to Chicago with his son to testify against Clay.