'MarineSniper' and 'Talhotblond's' IMs

March 19, 2010— -- A chance encounter in an online chat room led to a romance between a beautiful 18-year-old girl named "Jessi" and a handsome young Marine. But what she didn't know was that her "sweet sexy Marine" was actually a balding, 46-year old married man, Thomas Montgomery.

What Montgomery didn't know was that the beautiful temptress was actually a 45-year-old home-maker Mary Shieler, posing as her daughter "Jessi" without her knowledge.

Click here for more on their cyber romance

Unaware that they're both not who they say they are, "Talhotblond" and "MarineSniper" flirted in an online chat room for nearly two years, exchanging photos, gifts, phone calls and love letters. Their flirtation escalated into an intense virtual relationship, which Montgomery told "20/20" felt "more real to me than real life."

Click here for love letters sent between "Jessi" and "Tommy"

But when Jessi learned who her online love really was, she broke it off with Montgomery and took up with his young hunky co-worker, Brian Barrett. It was only a matter of time until the "MarineSniper" enacted the ultimate revenge.

On Sept. 15, 2006, Barrett was found dead in the parking lot where he worked, shot three times by a military rifle. News among co-workers spread of the love triangle and when police couldn't find Montgomery, they feared he was heading to "Talhotblond's" house in West Virginia.

Montgomery was sentenced to 20 years in jail in a plea deal for Barrett's murder.

An excerpt of one of "Talhotblond" and "MarineSniper's" intimate IM conversations is below.

MarineSniper1000 (6:26:40 PM):on friday or sat u can say goodbye forever to me and tommy

TalHotBlondbig50 (6:26:53 PM): why

MarineSniper1000 (6:27:03 PM): we r leaving for good

TalHotBlondbig50 (6:27:07 PM): no

MarineSniper1000 (6:27:29 PM): yes jessi u r having fun in ur life now so its time for us to leave

TalHotBlondbig50 (6:27:42 PM): no tom

TalHotBlondbig50 (6:27:51 PM)

: dont take tommy

MarineSniper1000 (6:28:09 PM): hes going with me u replaced him with timmy

TalHotBlondbig50 (6:28:29 PM): please dont say that

TalHotBlondbig50 (6:28:32 PM): its not true

MarineSniper1000 (6:28:50 PM): according to the text i got it is true

TalHotBlondbig50 (6:29:01 PM): no it isnt

MarineSniper1000 (6:29:31 PM): so its time for tommy to be put to rest

TalHotBlondbig50 (6:29:52 PM): i will leave

MarineSniper1000 (6:29:56 PM): i wish i had a perfect life like u and brian do

MarineSniper1000 (6:30:10 PM): that is up to u jessi its ur choice

TalHotBlondbig50 (6:30:15 PM)

: what does brian have to do with this

TalHotBlondbig50 (6:30:34 PM): ur not going to forgive this one

MarineSniper1000 (6:30:36 PM): he left a few copies of ur conversation on my tool box today

MarineSniper1000 (6:30:52 PM): half the company knows now

TalHotBlondbig50 (6:31:00 PM): knows what

MarineSniper1000 (6:31:09 PM): what u 2 talked about

TalHotBlondbig50 (6:31:14 PM): no tom

MarineSniper1000 (6:31:25 PM): how u told him im a ******* loser and predator

MarineSniper1000 (6:31:38 PM)

: i dont have a life

MarineSniper1000 (6:31:57 PM): 3 hours u 2 were talking about me

TalHotBlondbig50 (6:32:01 PM): what did u say to him

MarineSniper1000 (6:32:07 PM): i didnt

TalHotBlondbig50 (6:32:12 PM): why not

MarineSniper1000 (6:32:22 PM): its not worth it anymore

TalHotBlondbig50 (6:32:58 PM): i will get out of ur life tom ..... i have done to much damage to be undone now.... im so sorry