This year marks the 25th anniversary of quite a few Unsolved Mysteries cases. The dates next to the names are the dates when the disappearances/murders/offenses happened, not when they aired on TV. Let me know if I missed anybody.

Salvatore Spinnato (jumped bail after being charged with kidnapping and assault, January 1997)
Joshua Massengill (murdered, January 10, 1997)
Ennis Cosby (murdered, January 16, 1997)
Brenda Bowen (murdered by her estranged husband, January 28, 1997)
Richard Aderson (killed in a road rage incident, February 5, 1997)
Bryan Nisenfeld (went missing; a part of one of his legs was later found, February 8, 1997)
Wayne Davis (missing, February 12, 1997)
Jeanette Federico (went missing after her bank robber boyfriend was killed in a shootout, February 28, 1997)
Notorious B.I.G. (murdered, March 9, 1997)
Phoenix Lights (sighting of mysterious lights in the night sky in Phoeniz, Arizona, March 13, 1997)
Jesse Howell and Wendy Von Huben (teenage couple who were murdered in Florida, March 23, 1997)
Judith Smith (missing and later found murdered, April 10, 1997)
Monika Rizzo (murdered, May 28, 1997)
John Weeks (missing, May 31, 1997)
Rachel Timmerman (murdered by a man she was scheduled to testify against, June 3, 1997)
Shannon Verhage (went missing after her mother's murder, June 3, 1997)
Richard Vallee (escaped prison, where he was serving time for murder, June 5, 1997)
Kristen Modafferi (missing, June 23, 1997)
Natasha Jennings (died after a suspicious medical accident, July 8, 1997)
Kristine Westin and Kevin Woo (went on the run after being charged in the death of their newborn son, July 13, 1997)
Amy Bechtel (missing, July 24, 1997)
Robert James (baby killed in a road rage incident, August 1, 1997)
Randy Yager (fled after a warrant was issued for several counts of racketeering, September 1997)
Margie Jelovcic (ran off with her fugitive boyfriend, September 1997)
Brook Baker (murdered, September 7, 1997)
Jodie Bordeaux (shot to death in her own home, November 21, 1997)
Sabrina Aisenberg (missing, November 24, 1997)
Erica Richardson (murdered in her home by her estranged boyfriend, December 8, 1997)

Robert James was the young child who was also murdered in a road rage incident on 8/1/97. I think the case aired with the Richard Aderson case if I recall correctly

I'm shocked that the Richard Aderson murder has yet to have been solved.

I'm shocked that the Richard Aderson murder has yet to have been solved.
I agree. You would think that a green Jeep Cherokee with New Hampshire plates would be enough info to narrow down the pool of suspects. I’m also shocked that it hasn’t been solved in 25 years

Robert James was the young child who was also murdered in a road rage incident on 8/1/97. I think the case aired with the Richard Aderson case if I recall correctly

Added. I will go over more later and add the ones I'm missing.

Added the rest of the 1997 occurrences to the original post