I think Richie and Jackie were victims of their own ambition due to the rep Jackie Sr. had, therefore they felt like their were entitled to bigger and better things because:
A)Richie did 10 years in the joint
B)Jackie "My old was Jackie Aprile" Aprile Jr.

Richie and Jackie were both wildcards under Tony's regime, Richie was too old school and looked to undermine Tony at every turn while Jackie was too inexperienced and reckless to be a viable soldier or associate.

Much like in real life, murder, assassinations, accidents are all prevalent in the world of the Sopranos and we don't get closure as we would like.