|Real Name:||Rick Peterson|
|Appeared:||Mai Ka Wa Kahiko|
|Portrayed by:||Peter Greene|
"I want him dead before he hits the ground." Rick ordering Danny to kill Stan Edwards, Grace Williams's stepfather.
Rick Peterson is a dirty cop from New Jersey who appeared in the Season 2 episode, Mai Ka Wa Kahiko who was also once the former partner of Detective Danny Williams when Danny worked in New Jersey but their partnership came to a permanent end after Danny testified in Rick's trial which resulted in Rick being jailed for ten years and also leaving his once highly-decorated police career in disgrace after it was revealed that Rick was a dirty cop who had stolen money and drugs from various crime scenes that he and Danny investigated.
This convection also cost Rick his ex-wife, Kim who moved away and found someone and caused his son, Cole to disown his father.
Upon being released, Peterson took over the identity of deceased Marshal "Rick McGuire" where he headed to Hawaii, killing an air marshal who had tried to warn Danny of what was happening.
To ensure that Danny did what he was told, Peterson disguised himself as an HPD officer and took Grace away, imprisoning her in a locker before arriving to Danny and telling him that he was out of revenge for Danny testifying in Rick's trial despite Danny protesting that he had been under oath at the time. At gunpoint, Rick forced Danny to kill Stan, knowing that if Danny did so, then he would too end up in prison for murder while also losing the one thing that mattered to him more than anything in the whole word: Grace.
Luckily, though, Danny shot Stan in the right arm, leaving him bleeding but still alive while Danny's partner, Steve McGarrett arrived on scene too late to stop Danny from firing at Stan, not realizing that Danny had actually non-fatally shot Peterson.
Now that the situation had dissolved and with Stan receiving medical treatment, an enraged Danny headed over to Peterson to get a location as to where he was keeping Grace but when Peterson refused to say anything, Danny shot him in the right kneecap as Kono and Chin looked on in horror, causing Peterson to hit the ground.
Danny then leaned over Peterson and coldly told him that he would then shoot Peterson in the head if he didn't tell him where Grace was.
Peterson eventually gave up the location and Danny and Rachel were reunited with Grace and it's presumed that Peterson was eventually jailed for his crimes which included murder and the kidnapping of a minor.
- Grace Williams- (kidnapped, presumably intended to kill).
- Danny Williams- (took hostage).
- Stan Edwards- (shot by Danny, survived).