A former defensive back for the Jets who intercepted 17 career passes in eight seasons, Lynn's background is primarily as a secondary coach.
Although Lynn coached the 22nd ranked defense in the league and was let go when Jim Fassel was fired as New York finished last in the NFC East, the Giants were ninth in total defense two years ago.
"It is always a hard thing when you get released, because normally you aren't getting enough wins under your belt," Lynn said. "You usually go into a team with the same situation. I'm excited, because I'm going to a good team that is in the playoffs."
Lynn was the Giants' secondary coach when New York lost to Baltimore in Super Bowl XXXV. He inherits two Pro Bowl players in safety Ed Reed and cornerback Chris McAlister, headliners of a pass defense that ranked fourth in the NFL last season.
"I can't screw them up," said Lynn, once a candidate for the Jets' vacant secondary job and a job with the Buffalo Bills. "I have to be able to relate to them and improve them, so that they can stay at the quality level that they are at.
"Here is Chris McAlister, All Pro. How can you improve him? You can improve him by looking at his technique and fundamentals and help him refine and get even better."
New York was third in scoring defense in 2002 during Lynn's first year as defensive coordinator, allowing only 17.4 points a game.
Lynn has coached defensive backs Will Allen, William Peterson, Shaun Williams and Jason Sehorn. He has a history with Ravens defensive coordinator Mike Nolan, and Fassel recommended him to Ravens coach Brian Billick.
Billick was in New York last weekend and closely monitored the Jets' situation as Henderson received an offer Thursday night. Billick spoke with Lynn on Friday.
"To have someone like Johnnie available at this late date was very fortunate for us," Billick said. "He was looking at coordinator jobs. He had plenty of opportunities to be a secondary coach, so the timing was perfect for us."
Proximity to his children was one of Lynn's major considerations in joining the AFC North champions. Lynn's daughter attends Hampton University and his son will be a freshman at Rutgers this fall.
Lynn said Fassel, Billick's close friend, advised him throughout the interviewing process and gave Baltimore the nod.
"When I got the opportunity to talk to Baltimore and Brian Billick, I called him and he said, ‘That's the best place to be.'"
Lynn's connection to Fassel and his overall experience pushed him ahead of assistant secondary coach Dennis Thurman, who will remain with the Ravens in that capacity.
"The regard Jim has for him carried a lot of weight," Billick said.
Meanwhile, Henderson takes over a Jets defense whose personnel needs to be overhauled. The Jets were 28th against the run and 21st overall under Ted Cottrell last season.
"Donnie is a high-energy guy and has a lot of passion," Jets coach Herm Edwards said. "I like his demeanor."
Henderson carries a reputation for toughness and for guiding younger players through a roster transition. He was outspoken when a New York reporter asked him if he could inspire a listless defensive unit.
"Is that something I think I can handle?" Henderson said. "Whoever you are, when you come out to the practice field, make sure I know who you are so I can get you running, too."
NOTES: Billick noted a high degree of interest in defensive line coach Rex Ryan, including the Oakland Raiders, but has denied teams permission to interview him.
"His time will come," Billick said. "Right now, I need him here." …
Outside linebacker Adalius Thomas learned Monday that he won't be medically cleared to play in the Pro Bowl after elbow surgery.
Aaron Wilson writes for the Carroll County Times.