BROWARD (CBSMiami) – Andrew Milligan battled addiction and it wound up costing him his life.

In September 2018, Milligan, 27, relapsed and searched for a high. His path led him to Jean Jameson, federal drug investigators and Milligan’s father say. Andrew’s father, Paul, said his son was searching for heroin. Instead, he got fentanyl.

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“He relapsed,” Milligan told CBS 4 News. “He went to this guy to get high and he thought he was buying heroin and he got sold fentanyl and here we are.”

That dose of fentanyl killed Andrew at a Fort Lauderdale sober home. In many similar cases, the death investigation would end there but dogged members of a South Florida law enforcement task force worked to prove that Jameson provided Milligan with the fatal dose of fentanyl. Earlier this year, Jameson became the first person in Broward County to be charged with such a crime. Last week, Jameson pleaded guilty in federal court and received a sentence of 30 years in prison. Paul Milligan was ecstatic.

“We gotta make these dealers aware that we’re not taking this anymore and they need to know what they’re up against,” Milligan said.

Milligan is grateful for the DEA-led task force called Operation Phantom Chase. A DEA spokesperson told CBS 4 News that all fentanyl cases are being pursued and investigated. Milligan hopes the increased law enforcement crackdown sends a message to fentanyl dealers.

“Some of the guys are willing to take the gamble for 5 years in jail but when they know they’re facing 20 or 30 years it may give them a second thought,” Milligan said. “Is it really worth it for a few bucks?”

Jean Jameson’s case might not be completely over. His lawyer, Jim Lewis, told CBS 4 News that Jameson cooperated with the feds in this case and provided information on others in the drug hierarchy. Because of that Jameson plans to ask the judge for a reduction in his sentence. Paul Milligan said he does not want that to happen and he will do whatever he can to prevent it.

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“He got what he deserves,” Milligan said.

Investigators say fentanyl cases are on the rise in South Florida. They’re also skyrocketing across the state. According to a statewide Medical Examiner’s report released this month, the drug that caused the most deaths in Florida in 2018 was fentanyl. The number is a staggering 2,348 deaths. The report also said that “occurrences of fentanyl increased by 29.5 percent and deaths caused by fentanyl increased by 35 percent” over 2017.

Experts say the synthetic drug fentanyl is 100 times more potent than heroin and that dealers know this when they lace other drugs with it to try and boost a user’s high.

Since Jameson’s case, Broward County has also begun prosecuting its first case related to a fentanyl-related death. Miramar Police arrested Bernard Gonzalez a few weeks ago for providing the fatal dose of fentanyl to Kelly Fitzgerald in March 2019. He faces up to life in prison if convicted of first degree murder.

Photos of Andrew Milligan reveal a joyful young man with an unforgettable smile. His father said he could play any sport and always lit up a room. His death left his father devastated.

“I love my son with all my heart,” Paul said, speaking to us over FaceTime in front of a wall of photos of Andrew and a shelf with an urn containing Andrew’s ashes. “He was my one and only child. I spent my entire life with him as my best friend and he’s gone now. I have him no more.”

Paul is thankful that he’s been given a sense of justice for his son’s death. He wants to do what he can so other suffering families can share that feeling.

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“I want to fight for (Andrew) and I want to fight for these other families that aren’t fortunate to have what I’ve been given,” Milligan said.