In the late 1990s and early 2000s, Tim Montgomery was among the fastest people on Earth. At the 1996 Olympics in Atlanta, he won a silver medal as part of the USA’s 400-meter relay team; in the same event at the Sydney Olympics in 2000, Montgomery took home the gold. Two years after that, he ran the 100 meters in 9.78 seconds at an international competition.

Then Montgomery found himself linked to the Bay Area Laboratory Co-operative (BALCO), the sports medicine facility investigated for dispensing performance-enhancing drugs to elite athletes. In 2005, the Court of Arbitration for Sport handed Montgomery a two-year ban from his sport. (The runner later admitted that he had used both testosterone and human growth hormone.) Needing to earn a living some other way, Montgomery teamed up with fellow Olympian Steve Riddick and started a lucrative check fraud scheme that netted them $1.7 million … and for Montgomery, a guilty plea on fraud charges that resulted in a 46-month prison sentence. While appealing that case, police in Virginia busted Montgomery for selling heroin. That added five years to his prison term, of which he ultimately served a little over four years.

One thing that Olympians can do when they return to civilian life: coach. Who wouldn’t want someone who competed in the Olympics to train their kids in that very sport? Well, if the coach in question is Doug Northway, an Olympic swimmer who went to prison on some revolting charges, no parents would want him as a coach.

Northway was a three-time Olympian. At the 1972 Summer Olympics in Munich, he won a bronze medal in the 1,500-meter freestyle, competed (but didn’t medal) in the 800-meter freestyle at the 1976 Summer Olympics in Montreal, and made the team for the 1980 Moscow Olympics, which the U.S. ultimately boycotted. After retiring from competition, Northway became a pastor and swim teacher in Tucson, Arizona. Up until 1995, that is, when a 9-year-old female student of Northway’s told her parents that the coach had attempted to fondle her. After an investigation and arrest, Northway stood trial for attempted child molestation. A judge found him guilty and sentenced him to four months in prison, a lifetime of probation, and an order to register as a sex offender.

Riddick Bowe is a well-known heavyweight boxing champion, taking the title in one of the sport’s golden eras, the ’90s, alongside guys like Evander Holyfield, whom he beat twice and lost to once. But before his 43-1 lifetime professional record, Bowe took the silver medal for the U.S. in Seoul in 1988 in the super heavyweight class.

In 1998, Bowe committed some shocking crimes against his kin. Seeking to rekindle his relationship with his estranged wife, Judy, Bowe kidnapped her and their five children at knife-point from their home in Charlotte, North Carolina, and forced them into a car to head to his house in Fort Washington, Maryland. When they stopped at a McDonald’s (as one does during a kidnapping attempt, apparently), Judy snuck into the bathroom and used a cell phone to ask a relative to call the police. Officers soon arrested the boxer.

Brain damage was an issue in the trial, as a psychiatrist testified that Bowe had sustained so many punches to the head in the ring that it had affected his judgment to the degree where kidnapping his family seemed like a good idea. In 2000, a judge in North Carolina sentenced Riddick Bowe to 30 days in federal prison, six months of house arrest, four years of probation, and an order to undergo medical treatment for brain injuries sustained in the ring.

His nickname was “El Pollo,” but Alex de Jesus was no chicken. After all, he willingly entered the ring as an amateur boxer in his native Puerto Rico before quickly moving up to big international matches in the early 2000s. The super lightweight took the silver medal at the 2002 Central American and Caribbean Games, as well as at the 2003 Pan American Games. From there, it was on to the 2004 Summer Olympics in Athens, where de Jesus fought two matches, winning one and losing the other, and failing to medal. Upon his return to Puerto Rico, de Jesus turned pro and won nearly all of his first 20 bouts. Then his career and life suffered some hiccups when, in 2010, he was arrested and sentenced to four-plus years in prison on domestic violence and weapons charges.

He resumed his career upon his release, as well as his troublingly violent ways. In 2016, de Jesus’ stepmother filed a criminal complaint against the 33-year-old boxer, claiming he attacked her. Just a few hours after Puerto Rican police put out a warrant for de Jesus’ arrest, he was shot 12 times while walking down the street.