Former Sussex County Chief Prosecutor Martin Cosgrove, who announced his retirement in late December, was arrested January 6 in relation to a hit-and-run in Seaford that occurred November 16. No one was injured in the accident, but Cosgrove was charged with driving under the influence.
“I was extremely disappointed to learn that one of our senior prosecutors in Sussex County, Martin Cosgrove, drove under the influence and damaged property in a hit-and-run. He has been charged and will be prosecuted,” Attorney General Kathy Jennings said. “I have stated before that the point of the law is to guarantee that, regardless of the individuals, we all play by the same rules. Prosecutors are agents of the law, but we are not and must not be above it.”
Prior to his arrest, Cosgrove was known as a strong prosecutor whose focus was on violent crime. He successfully prosecuted Tovar Cruz in 209 for a 2016 murder and rape in Georgetown, resulting in a 67-year sentence. He was also instrumental in dismantling a downstate organized crime enterprise in 2017, leading to two convictions for murder by it leader.
There have been few details released about the hit-and-run that led to Cosgrove’s arrest or how police identified him as the driver of the car. There is also no explanation for how police knew Cosgrove was impaired as he left the scene of the accident and was not arrested until several months later.
“This is a very sad moment for everyone who knows Marty well at the DOJ,” Jennings said. “He has been a decades-long friend and colleague whom I have always admired. And he ha been a deservedly well-respected prosecutor and member of the Sussex County bar who recently served as chief Sussex County Prosecutor. But our country’s casual attitude toward drinking and driving is out of hand, and it has to stop. This is a cultural problem and a public safety threat that we cannot tolerate – least of all among those with the privilege to enforce the law.”
Because there were no injuries, Cosgrove could face fines between $230 and $1,150 as well as 60 days in jail. His license could also be revoked for six months if he is convicted of leaving the scene of an accident. If he is convicted for driving under the influence, Cosgrove could face fines between $500 and $1,500, a mandatory license revocation of between one and two years and potential jail time up to 12 months, although this is often suspended for a first-time offender. He could also be ordered to install an ignition interlock device on his vehicle.
Delaware had one of the nation’s lowest DUI arrest rates in 2025 with one survey showing just 43 arrests per 100,000 drivers. Although full numbers are not available yet, approximately 2,000 drivers were arrested for DUI last year, down 50 percent from 2024.
