The Walking Dead star had been abusing the prescription painkiller Oxycodone over multiple years.
Recently, neighbors have spotted Jansen coming home looking “wasted” and “shabbily dressed.” One source said, “He'd come out of a car at 4 a.m. wasted. He said he was just coming back from a shoot. He looked destroyed.”
A couple years back Jansen relocated to Nyack, a city close to where he and Hayden grew up.
“When he moved out of here; he disappeared. Then his father came and got his stuff out and said, 'I have to get him out of here.' Then he left for a year,” a local spilled.
The year the former child actor left the town, he was in rehab for his drug abuse.
“When he came back he looked OK in the beginning. He looked like a different person. He came back straightened up. Then he went downhill from there,” one source noticed about the artist.
"He was very nice guy, very friendly, he was an artist and an actor. Very friendly and generous; he would always offer me help,” the insider added.
On February 19, Jansen's body was found in his home by friends Benjamin Brown, Joe Fails and Lars Arianti — after the graffiti enthusiast missed pre-determined plans.
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Jansen was "unresponsive" when he was found, and his pals performed CPR, though they had no luck.
According to the police report, Fails called 911 while the other friends contacted Jansen and Hayden's father, Alan “Skip” Panettiere. When the EMT’s arrived at the scene the Even Stevens alum was pronounced dead.
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Orangetown Police Sgt. Peter Maher said the cause of death has yet to be determined.
A close contact said that sister “Hayden is just inconsolable. He was her best friend and her only brother. He was such a nice guy but he lived on the edge.”
The brother-sister duo was last seen on January 24 when Jansen posted a picture on Instagram of Hayden giving him a haircut.
Daily Mail spoke to an insider about Jansen's drug abuse.