- "Son, you and I both know that there's casualties in this line of work."
- —Lewis Snart to Leonard Snart[src]
Raising Leonard and Lisa Snart
Lewis came upon a man talking to his son one night. The man gave him the Maximillian Emerald, which Lewis had been planning to steal in a number of days. He left, but not before leaving a cryptic hint that Lewis would become an abusive husband and father and that the man who broke into his home was actually his son from the future. Some days later, he attempted to sell the jewel to an undercover police officer, but was instead arrested, landing him 5 years in jail for larceny.
When he was released, Lewis began to take his anger out on Leonard. Eventually he had another child, a daughter Lisa, whom he would eventually come to take his anger out on also and left her with numerous scars.
Lewis was frequently in jail for extended periods at a time for armed robbery, aggravated assault and assault with a deadly weapon.
Because Lewis was frequently in and out of prison Leonard was forced to raise Lisa like she were his own daughter, rather than a sister in Lewis' absence.
Heist with Leonard Snart
40 years later, Lewis escaped from Iron Heights. He found his son and daughter while the two, along with Mick Rory, were committing a robbery. Lewis had his son kidnapped and his daughter injected with thermite. Lewis then threatened his son to work for him or he'd kill Lisa. When the Flash came to "rescue" Leonard, Lewis was shocked when he saw his son cover the Flash in ice. Lewis told his son he didn't think he had it in him and the two left. While planning on a heist, Lewis killed David Rutenberg who told his son to shut up. Without a tech guy, Barry infiltrated the team, volunteering to help as "Sam". Lewis was doubtful at first due to his youthful appearance but Leonard vouched for him. When they arrive for their next heist, Lewis, Leonard, and "Sam" pose as janitors. When their ID badges were failing, Lewis prepared to pull a gun, but "Sam" figured another way without the guards being killed.
When they arrived on the twenty-seventh floor, they spotted two security guards. Leonard and Lewis argued as Lewis was wrong about the timing. After "Sam" subdued them behind their backs, Lewis had "Sam" breach the security code. After "Sam" got them in, Lewis shot "Sam". When they arrived at the vault, Leonard froze the lasers and Lewis went to pick the lock. Lewis was told they had 125 seconds before the security system defrosts.
After they obtained the diamonds, the sirens went off and as they escaped, they were intercepted by the Flash. Lewis told his son to kill the Flash or he would kill Lisa. As soon as Cisco removed the thermite from Lisa, the Flash broke the news to Lewis. As Lewis turned around to his son, the latter fired his cold gun at him. In his last moments Lewis asked why Leonard did it as he always thought his son hated the Flash, but Lewis was told he was hated more.
Before going to prison, Lewis was a somewhat caring father, albeit not an ideal one. He did seek to protect his son from a stranger, unknowingly an adult Leonard from the future, although doing so recklessly, by cursing and pointing a gun at the intruder right in front of his young son before sending the child away from the danger and to his bed.
However, after spending years locked up in prison, Lewis became extremely arrogant, selfish, ruthless, immoral and unreasonable, these combined traits made him a very dangerous man, he had little to no regard for innocent lives, repeatedly proving he was willing to kill already neutralized guards without remorse. This extended to his own men, as he killed an associate for disrespecting his son, as only he was allowed to do it and killed his subordinates without hesitation once they were no longer useful to him, as demonstrated on Barry Allen, who was posing as a security expert.
Although Lewis was intelligent, his intellect was not at the same level as his son's, which, combined with his arrogance, made him a very sloppy criminal. He regularly disregarded his son's advice about timing and contingencies, completely disregarding Leonard's experience and reputation with thievery, and killed whoever annoyed him, even if they possessed skills which could be useful in other jobs, yet was too impatient to simply ignore them.
Following Lewis' release from prison, Lewis began to have no concern for his own family, when his kids were young, he regularly abused both Lisa and Leonard physically when he was angry, saying he was trying to teach them lessons, along with abusing his wife, which forced Leonard to raise his sister like she was his own daughter. This cruelty continued into his old age, as he blackmailed his own son into assisting him on his final heist by implanting a bomb in his own daughter's neck. These negative traits of Lewis' were what eventually led to his painful yet deserved/justified death at the hands of his own son, Leonard and the latter's Cold gun.
- "Convicted of larceny, armed robbery, aggravated assault, assault with a deadly weapon."
- —Caitlin Snow[src]
- Expert thief: Snart was an intelligent heist planner, like his son, except he did not mind casualties.
DC's Legends of Tomorrow
Behind the scenes
- In DC comics, the character is named Lawrence Snart, rather than Lewis, but he has the same role of the abusive father, who ruined Lisa Snart's life and forced Leonard to run away from home and start a life of crime.
- In a TV spot for "", Cisco nicknamed Lewis "Colonel Cold". For reasons currently unknown, this scene was cut from the aired episode, potentially due to the character's quick exit from the show. The nickname was later used for Ray Palmer's brief alter-ego.
- Lewis' line, "Nobody talks to my son that way. Nobody", after killing David Rutenberg is reminiscent of the Justice League episode "Twilight", in which Darkseid (also voiced by Ironside) said a similar line while killing Desaad with his omega beam.
- Ironside played Sam Lane in Smallville beside Peyton List who played Lucy Lane in Smallville. In The Flash, the two actors play a father and daughter once again.