he s always very positive and very upbeat, very kind. he s a pleasure to work for. reporter: and everyone else police spoke to said the same. gil nunez seemed to have nothing to hide. what s more, after weeks of investigating, there was still no clear cause of death. so all investigators could do was wonder if the love triangle was just an interesting story that had nothing to do with tom s death. but that would all change when nearly the two months paf tom kol moon died, the toxicology reports finally came in and they were a shocker. we found out there was a conscious sedative called medazolam in tom s system. nobody ever heard of it before. at least in our field. you had never seen it in a murder before or as a street
patient of gil s and has always admired his generosity. does a lot of volunteer work in poor areas. reporter: did he ever say why he likes to do that? i think he s a man who cares. it s as as simple as that. i mean, he cares about his patients. and he cares that about, you know, people having access to good dental care. reporter: he was a member of the local chamber of commerce, a volunteer firefighter, voted one of the top hudson valley dentists five times, and chosen to endorse products in online ads. i m dr. gilberto nunez. i m a practitioner in kingston, new york. it was a very thriving practice. we were v we re very busy. reporter: his office manager, irene prehn, has worked for gil for 13 years. he s always very positive and very upbeat, very kind. he s a pleasure to work for. reporter: and everyone else police spoke to said the same. gil nunez seemed to have nothing to hide. what s more, after weeks of investigating, there was still no clear cause of deat
reporter: and after all the additional testing, the medical examiner finally had a cause of death, acute midazolam poisoning. investigators took everything they had to a special prosecutor and argued they were sure gilberto nunez had killed the man he called his best friend. i don t think that nunez was ever a friend to kolman. not for a minute do i believe that. he is a master manipulator. he lives to manipulate. i believe he drew tom in because he wanted to be closer to the wife and have access to the wife. reporter: nearly four years after tom s death, gilberto nunez was indicted for second-degree murder. how did that feel when you got that news? i cried.
passed. so she was ruled out, in in our eyes. reporter: that left one person policed needed to talk to again, her former lover, gil. and this time, they planned to confront him with all their suspicions. right there we stop. right there we stop. coming up was that mystery suv really gil s? your car is on the road and you were driving it. and the sedative in tom kolman s system. i looked into reporter: ulster police had been keeping an eye on local dentist, gil nunez, since they learned he d had an affair with tom kolman s wife. but now they believed tom s death was no accident and suspected a medical sedative was somehow to blame. so they decided it was time to bring gil in for another talk. are you and linda still we re close. it woulda lasted approximately seven hours. reporter: that s a long time. it was. there was a lot to cover. our biggest thing was the midazolam. the other thing was the vehicle. reporter: a team of investigators took turns c
reporter: what are you thinking when you hear that? well, i m thinking a couple things. i m thinking, that s gonna be a problem at trial because of the contamination. but i m also thinking, thank god, we get a little break. reporter: and after all the additional testing, the medical examiner finally had a cause of death, acute midazolam poisoning. investigators took everything they had to a special prosecutor and argued they were sure gilberto nunez had killed the man he called his best friend. i don t think that nunez was ever a friend to kolman. not for a minute do i believe that. he is a master manipulator. he lives to manipulate. i believe he drew tom in because he wanted to be closer to the wife and have access to the wife. reporter: nearly four years after tom s death, gilberto nunez was indicted for second-degree murder. how did that feel when you got that news? i cried. we all cried pretty hard. it felt it felt good in that,